Economic Analysis of Sustainable Coffee Production in Vietnam
Thong Quoc Ho
Submitted in fulfilment of the requirements for the degree of
Doctor of Philosophy
School of Economics and Finance
Faculty of Business
Queensland University of Technology
Principal supervisor: Dr Viet-Ngu (Vincent) Hoang
Associate supervisor: Prof. Clevo Wilson
2018
Statement of original authorship
The work contained in this thesis has not been previously submitted to meet requirements for an award at this or any other higher education institution. To the best of my knowledge and belief, the thesis contains no material previously published or written by another person except where due reference is made.
Signature: QUT verified signature
Date: June 2018
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Keywords
Coffee, cost, data envelopment analysis (DEA), efficiency, environment, farming, irrigation water, material balance principles (MBP), meta-frontier, meta-technology ratio
(MTR), nutrient, stochastic frontier analysis (SFA), Vietnam.
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Abstract
Vietnam is the second largest coffee producer in the world. The little literature reports that coffee farming in Vietnam has been increasingly economically and environmentally unsustainable. More specially, few studies documented that the consumption of chemical fertilisers and irrigation in Vietnam coffee farms are much greater than the average levels in other major coffee producing countries. Environmental regulations in Vietnam appear to be not sufficient while voluntary participations in sustainability certification programs become increasing popular. However, there is little empirical research that examines both economic and environmental performance of coffee farms in Vietnam. This thesis aims to enhance the understanding of the economic and environmental sustainability of Vietnam’s coffee farming sector.
The author has conducted surveys to collect data from 1,063 farms. Apart from coffee industry background and socio-economic profile of coffee farmers participated in the main survey, this thesis includes four empirical studies that assess a variety of the economic and environmental performance of the Vietnam’s coffee farming sector using the collected data. The first study investigates the productive efficiency of different farming systems, using a multiple output input stochastic distance function. The major findings show that combination of coffee and other industrial crops deliver the highest efficiency levels. The second study examines eco-efficiency and its variation across sustainability certified and non-certified farms. The empirical results of the second study indicate great potential improvement in the eco-efficiency level across coffee farms.
Results also show that although certified farms are likely to perform better than non-
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certified counterparts, the difference between these two groups appears to converge overtime. The third study provides an examination of potential trade-off between cost and nutrient efficiency. An elaborative material balance principles (MBP) based efficiency is proposed to decompose the production technology set into four distinct groups of sampled farms. Each group of farms should pursue differing strategies to improve cost and environmental performance. The findings also suggest that not all farms necessarily are faced trade-offs between cost and nutrient efficiency. Certified farms are generally more environmentally and cost-efficient than non-certified ones and this difference disappears overtime. The last study focuses on irrigation water efficiency using a sub-vector DEA meta-frontier technique. The findings suggest a significant potential to improve water efficiency and, advanced technologies are likely to have a much larger impact on the irrigation water efficiency than voluntary participation in sustainability certification schemes. Policy implications drawn from these studies are discussed in the thesis.
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Table of Contents
Statement of original authorship ...... i Keywords ...... ii Abstract ...... iii Table of Contents ...... v List of tables ...... x List of figures ...... xi List of appendices ...... xi List of abbriviations ...... xii List of publications and presentations ...... xiii Acknowledgements ...... xiv
Introduction ...... 1
1.1 Background ...... 1 1.2 Research problems: unsustainable coffee production in Vietnam ...... 3 1.3 Research questions ...... 6 1.4 Specific research objectives ...... 11 1.5 Methodologies ...... 11 1.6 Contributions ...... 12 1.7 Thesis outline ...... 15
Industry background ...... 20
2.1 Introduction ...... 20 2.2 Coffee production in Vietnam ...... 20
2.2.1 Overview of coffee production in Vietnam ...... 20 2.2.2 Primary Vietnamese coffee farming characteristics ...... 21
2.3 Sustainability certification programs in Vietnam ...... 22 2.4 Policy context ...... 24 2.5 Overview of studies on coffee production ...... 26
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Study design ...... 29
3.1 Introduction ...... 29 3.2 Hypothesis and overall objective ...... 29 3.3 Research aims ...... 30 3.4 Study site, data and ethics ...... 31
3.4.1 Study site ...... 31 3.4.2 Data and ethics ...... 32
3.5 Methodological reviews ...... 33
3.5.1 Overview of efficiency analysis ...... 33 3.5.2 Methodological review of environmental efficiency ...... 34 3.5.3 Indicator approach ...... 35 3.5.4 Frontier- based approach ...... 37 3.5.5 Materials balance-based approach ...... 38 3.5.6 Nutrient efficiency ...... 39 3.5.7 Irrigation water efficiency ...... 40
Socio-economic industry profile ...... 43
4.1 Introduction ...... 43 4.2 Demographic characteristics ...... 44 4.3 Economic profile of coffee farming ...... 48 4.4 Conclusion ...... 60
Diversification and Productive Efficiency ...... 62
5.1 Introduction ...... 62 5.2 Literature review ...... 65 5.3 Input distance function ...... 69 5.4 Empirical model specifications ...... 72 5.5 Farming systems and data collection ...... 75 5.6 Empirical results ...... 78
5.6.1 Maximum likelihood estimates ...... 78 5.6.2 Inefficiency model ...... 80 ______Economic Analysis of Sustainable Coffee Production in Vietnam vi
5.6.3 Relative efficiency levels of differing farming systems ...... 81
5.7 Discussions ...... 84
5.7.1 Evidence of agronomic benefits between coffee and other industrial crops...... 84 5.7.2 Why coffee farmers still choose rice ...... 86
5.8 Conclusions ...... 87
Eco-efficiency analysis of coffee farming ...... 89
6.1 Introduction ...... 89 6.2 Literature review ...... 93 6.3 Methodology ...... 97
6.3.1 First stage: Frontier eco-efficiency ...... 97 6.3.2 Second stage: Fractional regression models (FRMs) ...... 100
6.4 Empirical strategies ...... 102
6.4.1 Data descriptions ...... 102 6.4.2 Variable selection ...... 102 6.4.3 Weighted number of coffee trees ...... 105
6.5 Results ...... 106
6.5.1 Comparison of eco-efficiency between certified farms and non-certified farms ...... 106 6.5.2 Eco-inefficiency variance analysis ...... 112
6.6 Conclusions ...... 116
Trade-off Analysis between cost and nutrient efficiency ...... 119
7.1 Introduction ...... 119 7.2 The MBP approach to cost and environmental efficiency measure ...... 122 7.3 Existing approach to analysing a trade-off between cost and nutrient efficiency ...... 123 7.4 Elaborative approach of MBP cost and environmental efficiency ...... 127 7.5 Empirical strategies ...... 129
7.5.1 Study site and data ...... 129 7.5.2 Model specifications ...... 131 ______Economic Analysis of Sustainable Coffee Production in Vietnam vii
7.5.3 Efficiency results ...... 134 7.5.4 Analysis of cost savings and reduction in nutrient consumption ...... 136 7.5.5 Trade-off between economic and environmental performance analysis ...... 139 7.5.6 The role of the sustainability certification program ...... 143
7.6 Conclusions and policy implications ...... 146
Irrigation water efficiency ...... 149
8.1 Introduction ...... 149 8.2 Irrigation water and certification in Vietnam coffee farming ...... 153 8.3 Empirical strategies ...... 155
8.3.1 Sub-vector DEA meta-frontier models ...... 155 8.3.2 Irrigation water-oriented meta-technology ratio (MTR) ...... 158 8.3.3 Efficiency econometric models ...... 159 8.3.4 Data and variables ...... 160
8.4 Result and discussion ...... 163
8.4.1 Efficiency and irrigation meta-technology ratio...... 163 8.4.2 Variation in irrigation water efficiency and sustainability certification...... 168
8.5 Conclusions and policy implications ...... 173
Syntheses, conclusion and policy options ...... 176
9.1 Introduction ...... 176 9.2 Key findings ...... 177
9.2.1 Efficient farming systems ...... 177 9.2.2 Eco-efficiency of Vietnam’s coffee farming sector ...... 178 9.2.3 The nexus between cost and environmental efficiency ...... 179 9.2.4 Irrigation efficiency ...... 181
9.3 Management and policy implications ...... 181
9.3.1 The choice of farming systems by coffee farmers ...... 182 9.3.2 Improving quality rather than rapid expansion of certification schemes ...... 183 9.3.3 Promoting efficient use of material inputs ...... 184 ______Economic Analysis of Sustainable Coffee Production in Vietnam viii
9.3.4 Promoting the use of advanced irrigation technologies ...... 185
9.4 Limitations of the thesis...... 186 9.5 Further research ...... 187 9.6 Conclusion ...... 188
Bibliography ...... 191 Appendix ...... 211 Appendix 1: Derivation of output complementary effect ...... 211 Appendix 2: Weighted number of coffee trees ...... 213 Appendix 3: Mean efficiency of farms dropped out and joined in certification programs ...... 213 Appendix 4: Ethics approval and survey ...... 214
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List of tables
Table 4.1: Demographic characteristics of surveyed coffee farmers ...... 45 Table 4.2: Descriptive statistics of economic profile (measured in million VND per ha) ...... 49 Table 4.3: Economic profile of coffee production over crop years ...... 51 Table 4.4: Economic profile of non-certified vs certified farms ...... 57 Table 5.1: Descriptive statistics of variables ...... 77 Table 5.2: MLE for the stochastic input distance function ...... 79 Table 5.3: Inefficiency model ...... 81 Table 5.4: Complementary effects and diversification efficiencies ...... 82 Table 5.5: Characteristics of rice versus non-rice farms and coffee-rice versus other farms ...... 86 Table 6.1: Recent studies on the effects of certification in coffee production ...... 93 Table 6.2: Non-certified and certified farm categories ...... 102 Table 6.3: Descriptive statistics ...... 103 Table 6.4: Mean eco-efficiency levels ...... 107 Table 6.5: Tests for equality of eco-efficiency distribution ...... 110 Table 6.6: Factors affecting eco-efficiency ...... 113 Table 7.1: Descriptive statistics of variables ...... 130 Table 7.2: Cost and environmental efficiency measures ...... 134 Table 7.3: Cost and environmental performance ...... 137 Table 7.4: Changes in cost and nutrient usage by different groups of farms ...... 140 Table 7.5: Efficiency between certified and non-certified groups ...... 144 Table 7.6: Efficiency between certified and non-certified farms over time ...... 145 Table 8.1: Descriptive statistics of production factors per weighted tree ...... 162 Table 8.2: Distribution of efficiency scores and irrigation MTR ...... 165 Table 8.3: Irrigation water efficiency random effect OLS models ...... 170
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List of figures
Figure 1.1 Coffee production by major producing countries (ICO, 2017a) ...... 1 Figure 1.2: Thesis outline ...... 19 Figure 4.1: Distribution of household head ages ...... 46 Figure 4.2: Family size distribution ...... 47 Figure 4.3: Education levels of the household heads ...... 48 Figure 4.4: Direct production cost per ha in million VND (excluding family labour cost) ...... 53 Figure 4.5: Irrigation water per ha (measured in m3) ...... 59 Figure 5.1 Three distinct farming systems...... 75 Figure 6.1: Kernel estimated densities of farm eco-efficiency scores ...... 109 Figure 8.1 Irrigation water meta-frontier efficiency ...... 157 Figure 8.2: Irrigation MTR distribution: sprinkle vs micro-basin ...... 168 Figure 8.3: Meta-technology ratio to the meta-frontier ...... 172
List of appendices
Appendix 1: Derivation of output complementary effect ...... 211 Appendix 2: Weighted number of coffee trees ...... 213 Appendix 3: Mean efficiency of farms dropped out and joined in certification programs ...... 213 Appendix 4: Ethics approval and survey ...... 214
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List of abbriviations
CAE Cost Allocative Efficiency CE Cost Efficiency CRS Constant Return to Scale DGP Data Generating Process DMU Decision Making Unit FEM Frontier-based Eco-efficiency Model FRM Fractional Regression Model IWE Irrigation Water Efficiency MBM material balance-based model MTR Meta-technology Ratio NAE Nutrient Allocative Efficiency NE Nutrient Efficiency OLS Ordinary Least Squares QUT Queensland University of Technology SD Standard Deviation TE Technical Efficiency VRS Variable Return to Scale
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List of publications and presentations
Publications:
Ho T.Q., Hoang V., Wilson C., Eco-efficiency analysis of sustainability-certified coffee production: Evidence from Vietnam. Journal of Cleaner Production (2018), https://doi.org/10.1016/j.jclepro.2018.02.147. (Chapter 6).
Ho T.Q., Hoang V., Wilson C., Nguyen T., Which farming systems are efficient for Vietnamese coffee farmers? Economic Analysis and Policy (2017), http://dx.doi.org/10.1016/j.eap.2017.09.002 (Chapter 5).
Ho T. Q., Measuring Environmental Sustainability of Coffee Production Using Econometric and Frontier-Based Models: Vietnam as a Case Study. EEPSEA Research Report No. 2017-RR6. Economy and Environment Program for Southeast Asia, Laguna, Philippines. (Chapters 6, 7 and 8).
Presentations:
Ho T.Q., Hoang V., Wilson C., The nexus between cost and environmental performance of coffee production in Vietnam. 14th Western Economic Association International (WEAI) (2018). (Chapter 7).
Ho T.Q., Hoang V., Wilson C., Eco-efficiency analysis of sustainability-certified coffee production: Evidence from Vietnam. 61st Annual Conference of the Australian Agricultural and Resource Economics Society (2017). (Chapter 6).
Ho T.Q., Hoang V., Wilson C., The nexus between cost and environmental performance of coffee production in Vietnam. School of Economics and Finance, Queensland University of Technology (Brownbag Seminar) (2017). (Chapter 7).
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Acknowledgements
Since I enrolled in my PhD program at the Queensland University of Technology
(QUT), I have received great assistance and guidance from individuals and institutions.
First, I would like to express sincere thanks to my supervisors, Dr. Viet-Ngu Hoang and
Prof. Clevo Wilson, who have continuously guided and encouraged me throughout my
PhD journey. I am very grateful to them for the opportunity to learn from their experiences and for helping me to develop my research skills.
I would like to express my great gratitude to Prof. Sean Pascoe and Dr. Son
Nghiem who served as my confirmation panel members for their helpful comments and suggestions. Their invaluable advice on my proposal kept track of the studies presented in this thesis.
The school of Economics and Finance (QUT) has provided great academic support and excellent learning and working environment for which I am very appreciative.
I gratefully acknowledge the Australia Awards Scholarship for providing financial support for my PhD program. I am also thankful for the financial support I received from the Economy and Environment Program for Southeast Asia (EEPSEA) under the research grant number PCO15-0724-011, for field research and data collection.
Much appreciation is extended to data collection team members including Hoang
Anh Vu, Lang Van Trinh, Nguyen Trong Su, Huynh Trung Cao, Mai Thi Thoa, Dinh
Thi Anh Nguyet and Doan Thi Hong Ha.
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I am most thankful to the coffee farmers in Dak Lak, Lam Dong and Gia Lai provinces for participating in a survey that conducted in 2015, for sharing their production data and insight knowledge about coffee farming with me.
I am grateful to my family and friends. I am especially thankful to my wife, Thu
Hoang who have exhibited the supreme virtue of patience and understanding. I am most grateful to my son Quan Ho, and my little daughter, Linh-Dan Ho, born during my PhD journey, for offering me joys and great happiness every day.
Special thanks go to my dearest Australian family, Kim Rivera, for their support, caring and friendship that they have silently offered during my journey.
I am indebted to more people than I can name. Thank you all for being present in this unforgettable stage of my life.
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Introduction
1.1 Background
There are two primary types of coffee, Arabica (C. arabica) and Robusta (C. canephora), both with a long development history. It is believed that Arabica coffee was first discovered in the highland forests of Ethiopia (Murthy and Madhava Naidu, 2012).
The first semi-cultivation of Robusta was on the islands of Lake Victoria and in the north of Kagera, Tanzania (Waller, Bigger, & Hillocks, 2007, p. 6). Today, coffee is cultivated in more than 60 tropical countries most of which are developing countries and mainly carried out by smallholder farmers. In contrast, the consumption of coffee beverage is largely in developed countries. Coffee production is a billion-dollar industry for the major developing country producers Brazil, Vietnam, Columbia and Indonesia.
Figure 1.1 Coffee production by major producing countries (ICO, 2017a)
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In recent years, coffee has played an important role for many developing economies. Since 2012 annual total global coffee production has been approximately
150 million bags (60-kilograms). Approximately 78% was exported (ICO, 2017a) and was valued around US $20 billion. In the past the value of exports over the period 1997-
2005 has ranged from about US $5 to $12 billion, (Mohan, 2007). As shown in Figure
1.1, overall, coffee production has dramatically increased globally over the past decade.
In the current crop year, 2017/18, it is forecast that world production will reach approximately 159 million bags, of which 111 million are estimated to be exported.
Overall, coffee is one of the biggest trading commodities in the developing world.
There are four major coffee-producing countries which account for around 70% of total global production. Brazil is the world’s leading coffee producer with an output of over 50 million bags annually. 75% is Arabica and the rest Robusta. About 65% of the country’s production is for export. The second largest coffee producing country is
Vietnam, which is the world’s largest Robusta producer. As indicated in Figure 1.1, since 1999, coffee production in Vietnam has increased dramatically. Between 25 and
30 million bags annually have been produced in recent years over 80% of which has been exported. The next major coffee producing and exporting countries are Colombia and Indonesia. Each has produced over 10 million bags annually in recent years, with about 70% of the national output exported. The rest of the coffee producing world includes Ethiopia, a number of Central American countries, Mexico and India (ICO,
2017a).
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The focus of the study presented in this thesis is on Vietnam’s coffee farming sector, which globally has exhibited the most rapid growth in production. This crop is an important part of the Vietnamese agricultural sector, as discussed in Section 2.1.
1.2 Research problems: unsustainable coffee production in Vietnam
Although coffee production has played an increasingly important role in
Vietnam’s Central Highland economy and in the global coffee market, recent literature indicates that production has been undertaken in a highly unsustainable way in terms of degradation of environmental resources and economic outcomes which affect the welfare of farmers. In particular, the literature has highlighted a number of resultant environmental, economic and social challenges for Vietnam’s coffee production (Dzung et al., 2011, and Marsh, 2007). There is mounting evidence that more chemical fertilisers and water have been used in coffee production than in other crops in Vietnam (Dzung,, et al., 2011; Kuit et al., 2013). In terms of chemical fertiliser consumption, in 2010
Vietnamese farmers applied on average 156 kilograms of nitrogen and phosphate fertilisers per hectare (ha) of arable and crop permanent area (FAO, 2014), while coffee plants requires up to 800 kg of nitrogen per ha in order to be able to achieve sufficient output quantity (Bruno et al., 2011). Comparing internationally, coffee production, in order to be profitable, is believed to require more fertilisers in Vietnam than in other countries. As noted by Marsh (2007), Vietnamese coffee farmers can only be profitable if coffee trees are grown intensively with large amounts of fertilisers (approximately 2 tonnes of chemical fertilisers per ha per year), compared with 63, 102, and 76 kilograms per ha for agricultural production in the Philippine, Thailand, and Indonesia respectively
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(FAO, 2014). The surplus nitrogen and phosphate content of inorganic fertilisers used in agricultural production injected into the water system is cited as being the cause of serious environmental problems (Hoang and Nguyen, 2013).
Irrigation water is also an environmental resource that is over-applied in coffee production in Vietnam1 (D’haeze et al., 2003; Dzung et al., 2011) . Although coffee farmers extract a large amount of water for coffee plantations, they currently do not pay user fees. In fact, D’haeze et al. (2003) have argued that lack of regulations in the use of water is one of the reasons leading to over-irrigation in coffee production and which may accordingly degrade groundwater sources. If there is no policy change in relation to water use, it could be expected that some farms will over-irrigate, creating water shortages for other farms including coffee and non-coffee farms. In a broader context, continued overuse of water in coffee production will negatively affect the entire agricultural production in Vietnam’s Central Highlands in the future.
Vietnamese coffee farmers are exposed to a number of risks that may lead to economic losses. Price volatility in general and reductions in prices in particular, have been the major challenges for coffee farmers. For example, during the coffee price crisis of 2001 prices declined to below production cost. A number of studies argue that one of the primary causes of this crisis was the significant expansion in coffee production
(Marsh, 2007), which was seen as a natural adaptation of farmers to high prices in the
1 Coffee farms in Vietnam use mostly underground water, meaning use of such water is tightly linked between neighbouring farms by being a common resource. Nitrogen and phosphorus compounds in chemical fertilizers can contaminate the soil and/or be transmitted into underground water systems polluting neighbouring farms.
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previous season (coffee prices peaked at historically high levels in the period, 1993-1995
(ICO, 2014).
Coffee farmers have also faced serious challenges including unexpected weather conditions, pests and diseases and the risk of other unforeseen events (Valkila, 2014).
However farmers currently have limited access to insurance services which could mitigate these risks (Gemech et al., 2011). This is an important deficiency given that investment in coffee farming is long-term with many uncertainties and risks associated with price fluctuations and unexpected climatic changes. In response to these risks, it has been argued that, on the one hand, coffee farmers could diversify their farming activities. On the other hand, there is some empirical evidence to show that specialization in coffee production could enhance productive efficiency and act as a mitigation strategy against these risks.
Given increasing environmental concerns from foreign and local consumers, coffee farmers have taken part in several internationally recognised sustainability- certified production practices. Several studies have proposed the expansion of these certification programs to deal with environmental concerns in Vietnam
(TECHNOSERVE, 2013, p.6). However, there lacks an informed analysis of benefits associated with these sustainability schemes2 with some studies showing that, in comparison to conventional farming, the economic benefits of certified coffee production for Vietnamese farmers are unclear (Kuit et. al. 2013). The literature shows
2 Over the past few years the total amount of Utz certified coffee has increased from 17,925 MT in
2009 to 38,669 MT in 2012, accounting for 21% globally of Utz certified coffee (Utz-certified, 2014).
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that small-scale coffee farmers in countries such as Ethiopia did not gain significantly from certification programs due to low productivity, an insignificant price premium and limitations in provision of credit and information (Jena et al., 2012). Coffee producers in
Nicaragua have experienced similar difficulties. Several authors including Valkila
(2009), have also argued that sustainable development in coffee production may lead farmers into a poverty trap due to low yields and an insignificant price premium compared to conventional growers. To date, none of these studies have examined the relationship between environmental efficiency and these certification programs.
1.3 Research questions
Although there are a number of empirical studies measuring efficiency levels and its variations across farms in agricultural production, few assess environmental performance in conjunction with economic benefits for coffee production, particularly in
Vietnam. Technical and cost efficiency varies from farm to farm due to different technologies and socio-economic factors. In addition, it is unclear whether crop diversification is an appropriate strategy to enhance economic efficiency due to a synergy effect, i.e., agronomic benefit. Environmental performance is a critical factor in sustainable coffee development, which may ensure economic benefits to farmers in the long-run. However, the literature (see, for example, Bacon, 2005; Wollni & Zeller
2007; Basu & Hicks, 2008; Wollni & Brümmer 2012), indicates that economic and environmental efficiency can vary considerably. However, there is a lack of empirical evidence of the dynamic trade-off. Since coffee is a primary crop in the region being researched, the role of economic and environmental efficiency enhancement can be
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significant in improving farmers’ welfare. In fact, many sustainable coffee production schemes aimed at improving economic and environmental dimensions have been adopted. Thus, empirical evidence of this trend is likely to be of interest to policymakers and other stakeholders involved in the coffee industry.
Therefore, the overall objective of this study is to provide a broad picture of both economic and environmental performance of coffee production in Vietnam. Specifically, it investigates the following research questions.
RQ1: What is the relationship between efficiency and levels of diversification/specialization?
As the literature review shows, empirical evidence is mixed on the question of whether coffee farms should pursue diversification or specialization strategies. This study will examine the relationship between economic and environmental efficiency and levels of diversification and specialization. Empirical evidence from the study is expected to provide information on whether coffee farmers in Vietnam should diversify or specialize to achieve further improvement in terms of economic performance due to a synergy effect, i.e., agronomic benefits. The concept of economies of scope and scale are used to identify whether diversification is beneficial for the efficiency of coffee production.
RQ2: Are there significant differences in the economic and environmental performance between sustainability-certified and non-certified farms?
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Using the same framework of production frontiers, the thesis will examine if eco- efficiency varies across two groups of farms - conventional farms and farms taking part in sustainability related certification programs.
Sustainable certification in the coffee industry has become increasingly popular.
However, the literature shows different outcomes for the costs and benefits associated with certification schemes and indicates a lack of empirical evidence on the level of environmental efficiency of certified coffee production. This study, therefore, provides an empirical comparison of both economic and environmental efficiency between certified and conventional coffee production.
Economic benefit is one of the most important incentives to attract coffee farmers to participate in certified production schemes. Accordingly, certified coffee production cannot be viable if farmers are unable to receive higher economic benefits than uncertified farmers. More importantly, given the limited market demand for certified coffee, certified coffee farmers with a low level of efficiency need to be encouraged to diversify out of certified coffee and choose alternative crops or conventional coffee production. This may provide better economic prospects for such farmers.
Additionally, there is an argument that coffee farmers should receive higher premiums for certified coffee if their production is environmentally friendlier (i.e., significantly higher in environmental efficiency). However, if there is no significant difference in environmental efficiency between certified and conventional coffee production, both farmers and certifiers should seek adjustments which would produce better environmental responsibility. The information needed for such adjustments which
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enhance environmental responsibility in coffee production and sustainable coffee production in the long-run is useful for all stakeholders, including coffee farmers, consumers, certifiers and policy makers.
RQ3: What are the determinants of variations in environmental and economic performance across coffee farms in Vietnam?
In order to propose appropriate policies for more sustainable coffee production, determinants of economic and environmental performance of Vietnamese coffee farms are essential to identify. This thesis will firstly examine levels of economic and environmental performance of farms. For measuring economic performance in terms of the technical, cost and cost allocative efficiency of coffee farmers, a production frontier analytical framework will be applied. In order to measure the environmental efficiency of farm this study will incorporate a wide range of environmental efficiency measurement techniques, i.e., an eco-efficiency approach and the Materials Balance
Principle in the production frontier framework. In the second stage, efficiency scores are regressed against socio-economic characteristics to identify sources of inefficiency.
RQ4: What are the trade-offs between cost and environmental efficiency and scenarios to pursue cost efficiency and/or environmental efficiency?
By incorporating both an economic and environmental efficiency assessment, this study will investigate whether there is a trade-off for coffee farmers between environmental and economic efficiency. Trade-off analysis provides an analysis of the current relationship between economic and environmental efficiency levels in farming.
This creates a basis for identifying the long-term total economic benefit that farmers ______Chapter 1: Introduction
may achieve in comparison to what they could have sacrificed to improve the current level of environmental efficiency in farming. Under the assumption of weak disposability3 of pollution, a negative economic-environmental trade-off is implied. In contrast, under the assumption of strong disposability4 of pollution, a farmer utilizes inputs more efficiently leading to a reduction of pollution. Thus, partly replacing chemical fertilisers with organic fertilisers may improve environmental efficiency given that coffee plants normally take a longer time to utilize organic than chemical fertilisers.
Hence, better environmental performance in the past may lead to higher economic efficiency in the future. This dynamic trade-off between environmental efficiency and cost efficiency is therefore examined. This is expected to provide empirical evidence on the relationship between economic benefit and environmental performance.
RQ5: What are the irrigation water efficiency levels? Is there a difference in water efficiency between certified and non-certified farms?
In addition to chemical fertilisers, irrigation water is a crucial input in coffee production. As identified in the literature, coffee cultivation heavily depends on irrigation water. There are serious environmental problems associated with water resources in coffee production: i.e., drought, over-extraction and regional shortage of
3 Weak disposability of pollution describes the situation where a farm can only reduce its pollution levels by decreasing outputs and pollution proportionally. In other words, reduction of pollution is costly
(Chung et al., 1997).
4 Strong disposability of pollution represents the situation where pollution can be reduced without incurring a cost in reduced outputs. This means that there is no private cost of pollution (Chung et al.,
1997). Also, see Macpherson et al. (2010) for a detailed explanation of strong and weak disposability.
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water. Thus, improving irrigation water efficiency is a strategic objective that the coffee farming sector could pursue to ensure better environmental outcomes.
1.4 Specific research objectives
Specific objectives are:
1. To examine the relationship between economies of diversification and efficiency
levels.
2. To identify differences in economic and environmental performance between
certified and conventional coffee production in Vietnam, and inefficiency
determinants.
3. To estimate economic efficiency (i.e., technical, cost and cost), environmental
efficiency (i.e., eco-efficiency, nutrient and water efficiency), and evaluate the
relationship between environmental and cost efficiency.
4. To examine the efficiency of irrigation systems which have different irrigation
technologies and water efficiencies between certified and non-certified farms.
1.5 Methodologies
The thesis employs a range of methodologies which can be categorised in two main groups. For the economic performance analysis the studies employ frontier frameworks. This included both parametric and non-parametric approaches. In chapter 5, a stochastic multiple output/input distance methodology is used. Chapter 6 uses a Data
Envelopment Analysis (DEA) eco-efficiency technique to estimate eco-efficiency scores. In the second stage, fractional regression and OLS are used to examine the
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drivers of eco-efficiency variation. In chapter 7, a DEA material principle based nutrient frontier and cost frontier are used to estimate cost and nutrient efficiency. Chapter 8 uses a sub-vector DEA meta-frontier technique to estimate irrigation water efficiency under different technologies. A standard OLS approach is used to examine the variation of irrigation efficiency under different irrigation technologies and the meta-technology.
More details about these methods are described in each of the studies.
1.6 Contributions
The literature indicates that there is a knowledge gap in the area of sustainability measurement of coffee production. This study is aimed at making an empirical contribution in the case of coffee production in Vietnam. The results are original and enhance the economic and environmental understanding of coffee production in
Vietnam. To our knowledge, then, this thesis provides several significant contributions.
First, this thesis is the first study examining the diversification efficiency of coffee production in Vietnam. Among different diversified and specialised farming enterprises, it is indicated that there may be agronomic benefits; i.e., a synergy effect from the joint cultivation of coffee and perennial crops. This indicates the transition of agronomic benefits into economic performance. It is noted in this context that in a developing country such as Vietnam, farmers still chose inefficient staple crops, such as rice, as a food security strategy.
Second, one of the primary purposes of sustainability certification schemes is to improve both economic and environmental performance of coffee cultivation. This
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thesis produces the first empirical examination of the economic and environmental performances of sustainability certification, i.e., certified farms versus non-certified farms. Certification schemes are likely to have a positive effect on eco-efficiency.
However, the level of eco-efficiency between certified and non-certified farms appears to converge over time. This convergence may be due to positive externalities of certification, less compliance with certification standards or a combination of these effects. This is useful information which can be used to inform various stakeholders about the gap between certification objectives and the real situation and how to bridge this gap.
Third, using the Material Balance Principles-based efficiency measure, this study presented in Chapter 7 proposes a new approach to classifying farms into four distinct groups. In terms of methodological contribution, it helps examining both efficient and inefficient farms, while previous studies only focused on technically efficient farms.
Furthermore, each group of farms faces with different problems (i.e., using unnecessary nutrients) and they should pursue different strategies to enhance better cost or environmental performance. This provides different scenarios in which coffee farms may choose to be both cost and environmentally efficient, more cost efficiency oriented or more environmentally friendly. This provides policy considerations on how farms could achieve better cost and environmental outcomes. For instance, the reconciliation between iso-cost and iso-nutrient lines may be helpful. This is valuable information for the development of tax and subsidy policies or water-pricing policies in terms of
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ensuring that more environmentally harmful inputs are costlier and irrigation water is priced using the nutrient shadow price.
Fourth, given irrigation water is a key factor in coffee production, further investigation is conducted into irrigation water efficiency under two distinct irrigation technologies of certified and non-certified coffee farming practices. This study confirms that modern irrigation technology, i.e., overhead sprinklers, is more productive than conventional technology. That is, modern technology has a significantly higher meta- technology ratio. This is important as over-irrigation is the most serious environmental challenges in coffee production. Note that one of the most important aims of certification schemes is to improve water efficiency. The empirical results suggest that irrigation technologies are better at enhancing water efficiency than by being sustainably certified. This information is useful for consideration as to whether certification schemes should incentivise coffee farmers to switch to modern irrigation technology.
Most importantly, this thesis provides a broader picture of the current economic and environmental performance of coffee production in Vietnam. That is, it seeks to go beyond focussing on improved economic benefits which are the “business as usual” aims of coffee producers. Primarily examined is economic viability in relation to the most serious environmental issues in coffee production. Hence, this dissertation offers a foundation for creating policies and management schemes that can support sustainable coffee production.
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1.7 Thesis outline
This thesis consists of nine chapters. Chapter 1 provides an overall summary of the information contained in the thesis. The background to coffee production in Vietnam and an overview of studies on coffee production are presented in Chapter 2. Chapter 3 provides information about the data sets used, the nature of ethics clearances and an overview of methodologies used. Chapter 4 provides a socio-economic profile of the
Vietnamese coffee farming industry. Chapter 5 to 8 detail the major studies of this thesis on the nature of coffee production in Vietnam as it relates to eco and productive efficiency. Chapter 9 summarise main findings of the empirical studies presented in this thesis and it offers policy options for the coffee farming sector in Vietnam and across the globe where production and management settings are similar.
Chapter 5 provides a comparative assessment of productive efficiency of three common coffee growing systems in Vietnam: mono-cropping, synchronization and segregation. Results from an input distance function approach deliver several important findings. First, the average inefficiency level is estimated to be approximately 18% and which vary significantly among the three farming systems. Second, the synchronised system of growing coffee and the other industry crops is found to be the most efficient.
Third, coffee mono-cropping is found to be less efficient than synchronised systems due to the presence of economies of scope between coffee and industrial crops. Fourth, the least efficient system is shown to be where cultivation of coffee and rice are only organisationally integrated. Other than efficiency, food insecurity could be a primary reason why coffee farmers diversify into rice. These findings also provide empirical
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evidence for the presence of agronomic benefits of synchronised systems which are translated into productive efficiency. Policy options aimed at promoting synchronised farming systems may therefore enhance both economic and agronomic benefits.
Chapter 6 aims at examining the eco-efficiency of sustainability certified and non- certified coffee farms. There is a belief that sustainability-certified coffee production helps increase economic benefits to farmers and reduces negative environmental impacts. However, international empirical evidence is not conclusive. This paper then, provides the first empirical examination of the differences in eco-efficiency between conventional and sustainability-certified coffee-growing farms in Vietnam.
Environmental pressures measured by the level of consumption of nitrogen, phosphorus, irrigation water, pesticides, herbicides, fungicides and land are investigated in relation to the value-added factor of coffee production. Empirical results show that, in each crop year, coffee farms could reduce environmental negative effects by more than 50% while holding the value-added of outputs constant. On average, sustainability-certified farms are found to be more eco-efficient than conventional farms but efficiency differences appear to converge overtime. This convergence may be due to positive externalities of certifications, less compliance to certification standards or a combination of these effects. Higher eco-efficiency levels are also correlated with farms located in higher elevations, having wind-break trees, and using sprinkler irrigation techniques.
In Chapter 7, cost and environmental efficiency are examined. The literature documents significant trade-offs between economic and environmental performance in many areas of agricultural production. However, there lacks research about such trade-
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offs in coffee farming, especially in Vietnam where significant overuse of nutrients and increasing voluntary participation in sustainability certification schemes are observed.
Also, past empirical studies focus only on the trade-off for technically efficient farms, while in the literature differing types of trade-offs exist. The present paper addresses these two main gaps in the literature by analysing different types of trade-offs between nutrient efficiency and cost efficiency for Vietnamese coffee farms in three crop years using the Material Balance Principles (MBP) efficiency frontier framework. Our study has several important findings. First, three distinct groups face different types of trade- offs with one group having no trade-off between production cost and nutrient consumption. Second, sustainability certified farms show higher cost and nutrient efficiency levels and have higher technical efficiency than non-certified farms.
Empirical results therefore suggest the need for both a more heterogeneous but also a more integrated policy approach to improve both cost and environmental efficiency of coffee farmers in Vietnam.
Chapter 8 focuses on an analysis of irrigation water efficiency under different irrigation technologies. As documented in the literature, the unsustainable use of irrigation water in coffee production is one of the most serious environmental concerns.
Many sustainability certification schemes aim to promote more sustainable water use; however, there is a lack of empirical evidence on the effects of those scheme on water efficiency. This study measures water efficiency and examines the effect of certification on water. Due to distinct differences between the two predominant irrigation methods - overhead sprinkler and micro-basin irrigation technologies - the meta-frontier
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framework is used to estimate water efficiency of certified and non-certified farms. To the best of our knowledge, this is the first study using the sub-vector DEA meta-frontier approaches to examine irrigation water efficiency. Results confirm that the sprinkler system is more advanced than the micro-basin irrigation technology while average water efficiency scores with respect to these technologies are less than 0.5, implying a large potential for farms to reduce water use. The effect of sustainability certification on irrigation water efficiency under different irrigation methods is examined. The results show that there is no significant impact of certification schemes on water efficiency.
Persuading farmers to switch to better technologies such as use of sprinklers is therefore recommended to reduce consumption of irrigation water.
Chapter 9 synthesizes the main findings from the major studies presented in this thesis. As well, a set of integrated policy implications and recommendations are developed. This is designed to assist the coffee farming industry in Vietnam to become more economically and environmentally viable.
An outline of the thesis is presented in Figure 1.
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Research problems:
Unsustainable coffee production in Vietnam: (1) environmental problems (overuse of chemical fertilisers and unsustainable extraction of irrigation water) and (2) economic inefficiency through excessive use of inputs
Research Aims: Economic performance Environmental performance Economic and analysis analysis environmental trade-off
Research Objectives:
Diversification and Eco-efficiency analysis: Trade-offs between cost Irrigation water productive efficiency sustainability certified and nutrient efficiency efficiency analysis versus non-certified di Approaches to Empirical Analysis:
Multiple outputs input Eco-efficiency modelling MBP-based nutrient Sub-vector DEA meta- distance function DEA and Fractional efficiency model frontier Stochastic frontier analysis regression DEA
Outcome: Provide empirical evidence to inform policy to achieve sustainable coffee production
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Industry background
2.1 Introduction
Vietnam’s coffee farming is one of the most important farming sectors in terms of its contribution to national export earnings as well as to the livelihood of a large number of households. To understand the current economic and environmental characteristics of this sector, information about historic and current production and relevant policies is important.
The purpose of this chapter is to provide a brief overview of coffee production in
Vietnam, the primary characteristics of which make coffee cultivation different to other countries, and to underline the importance of the industry for Vietnam’s economy and the global coffee market. This chapter also offers a detailed overview of the policy context within which Vietnam’s coffee farming industry operates and provides a summary of studies on coffee production.
2.2 Coffee production in Vietnam
2.2.1 Overview of coffee production in Vietnam
As cited in many previous studies, i.e., Dang and Shively (2008), coffee was first introduced by the French in the 1850s but remained an insignificant crop until the 1980s.
In the 1990s, Vietnam coffee production increased sharply with around an annual 30% growth rate. By the end of the decade coffee accounted for about 10% of the country’s annual export earnings. Production which was 1.31 million bags in 1990 increased to
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25.5 million bags in 2016 (Figure 1.1) when the total planting area reached 670 thousand hectares. In recent years, Vietnam’s share of global output has risen from 17% to 19%
(ICO, 2017b). Also, coffee production in recent times has earned Vietnam approximately US $3.2 billion in export earnings becoming one of the leading export earners for the country.
In Vietnam, out of 64 provinces, the five Central Highlands provinces of Dak Lak,
Lam Dong, Dak Nong, Gia Lai and Kon Tum produce about 90% of the country’s coffee output. This is equivalent to roughly 15% of global coffee production (Tran and Smith,
2017). According to the Sustainable Coffee Program (2013), coffee production currently provides the major livelihood for over 500 thousands households, who mostly reside in the Central Highlands. While coffee production and exports are clearly important to
Vietnam’s economy, to the Central Highlands people’s livelihoods and the global coffee market, its sustainability has been questioned.
2.2.2 Primary Vietnamese coffee farming characteristics
There are several characteristics making Vietnam coffee farming different to other major coffee producing countries. First, small-scale production is the typical production mode in Vietnam accounting for more 90% of coffee output. Each farm is on average between one to two hectares (Luong and Tauer, 2006). The average size of Brazilian coffee farms is around nine hectares (Waller et al., 2007, p.23). Second, Vietnam has, globally, the highest yield for coffee output being on average 2.5 tons per hectare (Tran and Smith, 2017). The figure for Brazil is approximately 1.6 (Rubio and Barros, 2017).
In a number of crop years, some Vietnamese coffee farmers have achieved yields of
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3.458 tons per hectare. This was the average yield of 644 farms surveyed between 2005 to 2009 (Amarasinghe et al., 2015). For Indonesia and other remaining coffee producing countries yields have been considerably lower (USDA, 2017).
As documented, while high-intensity Robusta cultivation brings high yields for
Vietnamese coffee farmers, the coffee sector has also faced many challenges. A dense monoculture of coffee trees with intensive use of chemical fertilisers and irrigation water is a typical coffee farming practice in Vietnam. As reported by Amarasinghe et al.,
(2015), the cost of fertiliser accounts for almost half production costs. Although irrigation water has no usage fee, labour cost for harvesting and irrigation accounted for about 34% of the production cost. It is noted that the variation in fertiliser application across farms and years is significant. This indicates that there is an opportunity to improve efficiency of fertiliser use, hence enhancing both economic and environmental benefits.
2.3 Sustainability certification programs in Vietnam
There are several certifiers actively providing certification services for coffee production. These certification schemes include Organic, Fair Trade certified, Rainforest
Alliance, Bird Friendly, Utz Certified, and 4C. A comparison matrix indicating each scheme’s main objectives and standards is available at the Specialty Coffee
Association’s website (Kline, 2009). In Vietnam, the major certifiers are 4C and Utz-
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certified (Utz): details of their standards can be found on their websites5. Overall, these certifications are aimed at improving economic, environmental and social sustainability through better farming practices. They cover both the issues of chemical fertilisers and irrigation water in focussing on the economic and environmental dimensions. Although both certifiers indicate the importance of the efficient use of these inputs in coffee production, neither provides appropriate doses of these inputs nor advocate particularly types of advanced technology, i.e., particular irrigation techniques.
Voluntary sustainability certification in coffee production is a market oriented strategy and this trend in certification has increased in Vietnam over recent years. Rising consumer concern about environmental and social sustainability has meant an increasing number of coffee roasters have committed to provide coffee that complies with sustainability certification standards. Being certified is largely based on cooperation between roasters or exporters and individual farmers or farmer groups. There are a number of roasters and exporters operating in the Vietnamese coffee market. But there is a lack of official statistics which detail certification programs. Relevant statistics are collected from reports of different stakeholders.
The certification trend among Vietnamese coffee farmers has expanded rapidly in recent years with approximately 33% of the coffee output in 2012 being certified by either
4C (20%), Utz (11%) or Rainforest Alliance (1%) (as cited in Boselie, 2016). According
5 Details of the indicators and standards of these certification schemes subsequently updated are accessible at their websites (4C: http://www.globalcoffeeplatform.org/resources/gcp- baseline-common-code; and Utz-certified: https://utz.org/?attachment_id=3623).
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to a presentation by a deputy chair of the Vietnam Coffee Coordination Board, the current certified area of coffee cultivation accounts for about 60% of the total coffee cultivated area. Another source estimated that give the level of increase in certification up to 2013, over 80% of Vietnam’s coffee supply would be certified by 2016 and thereby making certified coffee by far the most common type supplied (The Sustainable Coffee Program,
2013).
2.4 Policy context
Historically, there have been several particular policies contributing to the rapid growth of Vietnam’s coffee production. First, after the country’s reunion in 1975, the government of Vietnam implemented the “new economic zone (Doi Moi)” policy promoting state-sponsored migration to the Central Highlands region. This is also known as a period of privatisation and economic liberalisation (Dang and Shively,
2008). Second, the adoption of market-oriented policies by the country in the late 1980s and the collapse of the International Coffee Agreement (ICA) in 1989 (Waller et al.,
2007), enabled Vietnamese coffee producers to compete freely in the global coffee market (Luong & Tauer, 2006). These influences are accepted as being the main drivers promoting the significant growth of coffee production in Vietnam.
Vietnamese policy makers have recognised the many challenges facing development of the coffee industry, and in doing so have attempted to support its development in a sustainable manner. As cited in a recent report (IDH 2014, 4–5), a
Deputy Director of Vietnam’s Coffee Sector Coordinating Board, in the Ministry of
Agriculture and Rural Development (MARD) remarked: ______Chapter 2: Industry background
“To date, Vietnam’s coffee sector has made outstanding progress.
However, it faces many sustainability challenges. These include “hot”
development of cultivation area; exhausted soil; abuse of fertilizers;
inefficient water use, which leads to exhausted water sources in the
context of the global climate change; quality and food safety control;
outdated technologies; adding value to export products; and benefit-
sharing mechanisms between coffee farmers and companies to ensure
long-term business relationships.”
In 2013, the Extension Program for Sustainable Coffee Production in Vietnam was approved by MARD. This program has provided technical training for coffee growers.
Another program for coffee rejuvenation has provided coffee farmers with seedling support, technical guidelines for land preparation, root treatment and crop rotation and credit/loans for coffee production. In addition, the government has also implemented a program to restructure the agriculture and rural sectors and other rural development programs.
In 2014, the Ministry of Agricultural and Rural Development created a sustainable coffee development plan which encompasses the years through to 2020. The primary objectives are to (1) stabilise the coffee planting area of around 600 thousand hectares
(currently about 670 thousand), (2) maintain 80% under sustainability certified production, (3) maintain average yields of 2.7 tons per hectare, (4) sustain exports at approximately 1.6 million tons annually, and (5) derive annual export revenues of between US $3.8 to $4.2 billion.
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To date, there is no program that evaluates sustainable coffee production in terms of interdisciplinary aspects of its cultivation. Thus, this study is designed to produce policy options based on empirical evidence to enhance future sustainable coffee production.
2.5 Overview of studies on coffee production
Because of its importance for many developing economies, coffee farming has been the subject of numerous studies (see, for example, Giuliani et al., 2017; Chiputwa et al., 2015; Luong and Tauer, 2006). Although many have been centred on the technical aspects, e.g., genetic (Goldfarb et al., 2005), the majority have focussed on coffee farmers’ benefits and the effect of sustainability certification schemes ( see, for example,
Barham and Weber, 2012; Kilian et al., 2006; Méndez et al., 2010; Ruben and Fort,
2012; Wollni and Zeller, 2007). A review of 46 studies on the effect of certification on agricultural production by Blackman and Rivera (2011), showed there were 22 studies devoted to coffee farming. Since then, the number of studies on coffee farming has increased (for example, Bray and Neilson, 2017; Elder et al., 2013; Hardt et al., 2015;
Ibanez and Blackman, 2016).
There are several studies that examined cost and technical efficiency and inefficiency variations, although there are none investigating envrionmental efficiency.
Rios & Shively (2006) using constant return to scale DEA found that coffee farmers in
Vietnam’s Dak Lak province were technically inefficient, with an average score of 0.78.
Using the same technique, the authors also found that cost efficiency was relatively low with an average score of 0.39. This meant farmers would have been able to save 61% of ______Chapter 2: Industry background
production costs while maintaining the same output level. Another study also use the
DEA technique found a relatively low technical efficiency level for Vietnamese coffee farmers of 0.70 (Garcia and Shively, 2011). In addition, Ho et al. (2014) using the stochastic frontier analysis (SFA) technique found that the existence of inefficiency was statistically significant at an average level of 0.70 for coffee farmers in Dak Lak,
Vietnam. These imply a posibility of efficiency improvement in regard to less intensive use of input factors, since economic theory would suggest some benefits of specialisation.
In creating an inefficiency model for the seond stage, a series of socio-economic and geographical variables were incorporated. For example credit loan, formal education of the household head, farming experience and extension services were seen as key factors in efficiency improvement (Ho et al., 2014). Participation in a farming association was also shown to help coffee farmers be more efficient in Cote d’Ivoire
(Binam et al., 2003) and similarly in Costa Rica (Wollni and Brümmer, 2012). In addition, farming experience, other income sources rather than coffee, and age of the household head have been shown to be important efficiency determinants for speciality coffee production (Wollni and Brümmer, 2012). Other socio-economic factors affecting coffee production efficiency have also been identified in studies by Binam et al. ( 2003),
Rios & Shively (2006), Vedenov et al. (2007) and Wollni & Brümmer (2012).
Therefore, it is aruged that economic efficiency analysis using a panel data set for coffee produciton is necessary in order to produce robust empirical evidence given previous studies used only cross sectional data.
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Despite the many international studies on coffee farming, there are only a few devoted to coffee farming in Vietnam none of which examine economic and environmental sustainability. These previous studies have indicated coffee farming was being carried out at an unsustainable level (for example, Dzung et al., 2011;
Amarasinghe et al., 2015). A detailed review of studies on coffee farming examining economic and environmental performance are presented in Sections 4.2, 5.2, 6.1 and 7.1.
In short, none focus on a comprehensive assessment of both economic and environmental aspects of Vietnam’s coffee farming sector. In addition, the economic and environmental effect of sustainability certification schemes on Vietnam’s coffee production remains unclear.
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Study design
3.1 Introduction
From the overview of the literature in Chapter 2, it is clear there is only limited economic and environmental information available on the coffee farming sector in
Vietnam. However, in-depth information about the current level of economic and environmental performance is of significance for the development of evidence-based policy options promoting the future sustainable development of the coffee sector.
The purpose of this chapter is to provide information about the way in which the economic and environmental performance of Vietnam’s coffee farming sector is measured in this research paper. The research design includes a hypothesis, an overall research objective and research aims. This chapter also presents information on the scope and nature of data used, ethics and a review of methodologies used in the studies presented in this dissertation.
3.2 Hypothesis and overall objective
The literature indicates that Vietnam’s coffee farming sector has become economically and environmentally unsustainable given the exceptionally rapid expansion in both non-certified and certified coffee production in recent years. This motivates a comprehensive assessment of economic and environmental performance of the industry. Therefore, this thesis has focused on the following hypothesis: There is a potential to improve both economic and environmental viability of Vietnam’s coffee farming sector. ______Chapter 3: Study design
The overall objective of the research presented in this thesis is to enhance the understanding of the economic and environmental status and potential sustainable viability of the Vietnam’s coffee farming sector.
3.3 Research aims
Based on the hypothesis and the research objectives, the thesis pursues the following research aims:
Aim 1: Determine the level of productive efficiency of Vietnam’s coffee farming;
identify efficient farming systems and explain the reasons why current farming
systems exist.
Aim 2: Measure economic and environmental performance of the Vietnam’s coffee
farming via the eco-efficiency indicator, identify the drivers for eco-efficiency
variation and examine the difference in eco-efficiency between certified farms
and non-certified farms.
Aim 3: Measure economic and environmental performance of the Vietnam’s coffee
farming via two indicators, namely cost efficiency and nutrient efficiency, and
identify possible scenarios that farms could achieve cost efficiency, nutrient
efficiency and trade-offs between cost and environmentally efficient options.
Aim 4: Examine environmental performance via irrigation water efficiency under
different irrigation technologies and compare the irrigation water efficiency
between certified and non-certified farms.
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Aim 5: Discuss policy implications that support a sustainable future development of the
Vietnam’s coffee farming sector.
3.4 Study site, data and ethics
3.4.1 Study site
The research site of this study is the Central Highlands, the dominantly largest coffee-producing area in Vietnam. The Central Highlands region includes five provinces: Dak Lak, Lam Dong, Dak Nong, Gia Lai, and Kon Tum. In these provinces, soil and climatic conditions are especially favourable for industrial crop cultivation (i.e., coffee, pepper, and avocado). In 2015, the Central Highlands accounted for approximately 88 percent of the coffee planting area and coffee production in Vietnam
(Dries et al., 2015). Over 85 percent of coffee plantations are operated by smallholders, with a small production scale of 1–2 hectares (Luong and Tauer, 2006). In the region, certified coffee production has increasingly expanded in recent years. This trend is recognized as coffee farmers and other value chain partners adhere to predefined sustainable standards including social, environmental, and technical aspects. In the coffee sector in Vietnam, certified production has been mostly operated under cooperation between coffee farmers and roasters, and local or international exporters.
Common certification schemes that have actively operated in the region are UTZ, 4C, and Rainforest Alliance.
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3.4.2 Data and ethics
There are two datasets used to achieve the above outlined research aims which are largely based on primary data. Specifically, the dataset used in Chapter 4 was provided by the Department of Economics, Tay Nguyen University, Vietnam. More details about the survey are described in Section 4.5. This dataset includes aspects relevant to coffee production such as coffee output, cultivating area, information on input use and relevant farm characteristics. The second dataset used in the analysis in Chapters, 6, 7 and 8, covers various aspects of coffee production in terms of economic, environmental and social variables relevant to coffee production. The collection of this dataset was approved by the QUT Human Research Ethics Committee (approval number:
1500000663). A copy of the questionnaire is provided in Appendix A.
A mixed cluster and stratified random survey of 896 coffee farmers was conducted using a face-to-face interview technique in three provinces (328 farms in Dak Lak, 348 farms in Lam Dong and 220 farms in Gia Lai provinces). Data on three crop years
2012/13 to 2014/156 was collected for each farm. The selection of districts and communes where farms were located was based on several criteria including the importance of coffee as the key livelihood for farmers, geographical and ecological representation as well as the popularity of certified coffee production. Consultation with the local offices of the Department of Agriculture and Rural Development was carried
6 The crop year of coffee farming in Vietnam is similar to the calendar year. It starts in January and finishes in January of the following year. Therefore, hereafter the crop years 2012/13, 2013/14 and
2014/15 are used as years 2012, 2013 and 2014 respectively.
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out to reduce potential biases due to variations in economic conditions, production scale, as well as social dimensions across the three provinces. Each local administrative unit is considered as a cluster.
A structured questionnaire set was used in the survey. Prior to the main survey, focus group discussions and pre-tests were conducted to finalise the survey instrument.
The field survey was undertaken from September 2015 to January 2016. This was based on the fact that most coffee farmers use a log book or a diary to record their farming activities. Only in cases where they did not have a farming log book, were farmers required to recall information by memory. We acknowledge that recalled data could pose limitations on information accuracy and for this reason we asked for data for only three historical years. Some observations have missing data; hence and were accordingly removed.
3.5 Methodological reviews
3.5.1 Overview of efficiency analysis
In recent years, there has been an abundant addition to the literature on empirical analysis of farming activities. This literature focuses on the technical, cost and environmental efficiency of farmers. The term, ‘technical efficiency of an individual producer’, can be described as his/her ability to minimize input use in the production of a given output vector, or the ability to obtain maximum output from a given input vector.
The measurement of technical, allocative and economic efficiency was initially proposed
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by Farrell (1957) and has since attracted considerable attention by researchers who have attempted to narrow the gap between theory and empirical application.
Efficiency and productivity measurement is a longstanding area of study in economics widely used to gauge economic performance of a firm, industry or economy.
There have been two primary trends in efficiency analysis - econometric and mathematical. Since Aigner et al. (1977) proposed the SFA - known as the parametric approach - many studies have successfully been developed and applied to measure efficiency and analyse variations in efficiency (for example: Pitt & Lee 1981;
Reifschneider & Stevenson 1991; Kumbhakar et al. 1991; Huang & Liu 1994; Battese &
Coelli 1995; Alvarez & Arias 2004; Illukpitiya & Yanagida 2010; Yu-Ying Lin, Chen,
& Chen, 2013; Mutoko et al., 2014). Another technique known as the non-parametric approach was proposed by Charnes et al. (1978) based on mathematically linear programming to estimate efficiency scores as the first stage of Data Envelopment
Analysis (DEA). In the second stage the efficiency indexes are regressed by a vector of variables to examine the variation in efficiency. The DEA approach has been widely employed in many areas of economics e.g. agricultural economics and the measurement of industry and environmental efficiency (also see: Chambers et al. 1998; Coelli 1998;
Ara 2002; Amirteimoori et al. 2006; Lilienfeld & Asmild 2007; Munksgaard et al.
2007).
3.5.2 Methodological review of environmental efficiency
In agricultural production, environmental aspects have become an increasingly important benefit for farmers as well as for the global economy in the longer run.
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Pittman (1983) produced one of the first studies attempting to incorporate undesirable outputs in agricultural production into conventional efficiency indexes. He reveals that incorporation of undesirable outputs significantly affects the rankings. Using efficiency and productivity measurements based on production frontiers, many studies have attempted to integrate environmental performance of producers into technical and economic efficiency measures. See, for example, Färe et al. (1989), Reinhard et al.
(1999); Reinhard et al. (2000); Wossink & Denaux (2006); Coelli et al. (2007);
Lilienfeld & Asmild (2007); Lauwers (2009); Frija et al. (2009); Hoang & Nguyen
(2013).
Generally, there are two primary approaches to measuring environmental performance in agricultural production. The first focuses on the development of various indicators which can be used to describe differences across different systems (Wu &
Wu, 2012; Bell & Morse, 2008). The second approach employs production frontiers to derive efficiency and productivity measures and uses both parametric and non- parametric techniques to estimate relative efficiency. Both approaches examine relative performance as well as providing a temporal analysis of performance changes. The relative performance comparison and assessment are useful in evaluating the performance of individual firms or systems (hereinafter also called a decision-making unit (DMU)) relative to all other DMUs.
3.5.3 Indicator approach
Various indicators representing environmental performance are constructed by using the flows of both monetary values and physical values such as the content of
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materials or energy involved in the production process. Common physical indicators are energy balance, nutrient efficiency and thermodynamic energy efficiency. These indicators are also called agroecosystem performance indicators (APIs) (Tellarini and
Caporali, 2000) or agri-environmental indicators (AEIs) (Piorr, 2003). They describe the relationship between material (such as nutrients) and energy inputs and outputs. The balance represents the difference between energy or material (nutrient) inputs and those of the outputs. Thus efficiency reflects the ratio of energy or nutrients in inputs to those in outputs (Hoang, 2011, p. 4,5). In regard to ecological sustainability, the quality of energy and mass, defined as exergy (Wall, 1977), has been increasingly used to construct environmental or ecological indicators. This includes estimating cumulative exergy balance and exergy-based system transformity (Chen & Chen, 2007; Hoang &
Alauddin, 2010). Some studies have attempted to include all the flows of monetary value, energy, materials and exergy in order to analyse economic and environmental performance of production systems (see, for example, Tellarini & Caporali, 2000;
Hoang & Alauddin, 2010).
The indicator approach is simple to calculate and useful in providing information on the economic and environmental performance of individual DMUs. This approach does not, however, help to explain changes in the economic benefits and environmental performance of a network or an industry where relative efficiency levels among DMUs are taken into account (Hoang, 2011, p. 5). The drawbacks of the indicator approach can be overcome by the frontier-based methodology where efficiency and productivity are measured, based on production frontiers.
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3.5.4 Frontier- based approach
The frontier-based approach has been traditionally used to examine the relationship between a set of inputs and corresponding outputs of DMUs associated with production technology. This relationship represents the economic performance of individual DMUs compared with other DMUs. These measures can also be decomposed into two meaningful economic components - technical efficiency and allocative (price) efficiency (Farrell, 1957). A number of studies have developed and employed this approach to measure, not only technical efficiency, but also allocative, cost, revenue and profit efficiency using information on prices. In addition, it allows investigation of factors affecting variations in efficiency levels across DMUs. Information about key determinants of efficiency variation provides useful guidelines on how to affect these determinants in order to improve the efficiency of DMUs.
In terms of environmental efficiency measurement, both parametric and non- parametric techniques have been employed. Lauwers (2009) summarised two types of frontier-based eco-efficiency models and the advantage of the material balance based model (MBM). The first type, the environmentally adjusted production efficiency
(EAPE) model, considers pollution as either environmentally detrimental inputs or undesirable outputs, which are to be minimised. Therefore, technical efficiency can be estimated using an input/output oriented approach, or using hyperbolic or directional distance functions (Färe et al., 1989; Chung et al., 1997; Reinhard et al., 2000; Wossink
& Denaux, 2006)). However, these EAPE models are in conflict with fundamental thermodynamic laws, such as mass conservation (see: Coelli et al. 2007, Hoang & Coelli
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2011; Hoang & Nguyen 2013). The second frontier-based eco-efficiency model (FEM), examines relationships between economic and ecological outcomes, using the frontier framework. The primary use of the FEM is to assess relative environmental performance among DMUs. This is important given there are many types of environmental pressures caused by production and consumption activities.
3.5.5 Materials balance-based approach
The principle of materials balance explains that materials in inputs are transformed into outputs, including desirable and undesirable outputs (e.g., emissions) that can cause pollution (Ayres, 1995). Since the materials balance principle hold true in any cultural system, it has received increasing attention in efficiency literature. Reinhard &
Thijssen's (2000) study is one of the first attempts to address the materials balance issue.
The study used the materials balance principle to calculate the nitrogen pollution variable which is treated as an input variable in DEA models. Environmental efficiency is measured by contracting the pollution input variable, while holding the output and the conventional inputs constant. In another study Reinhard et al. (1999) treat nitrogen surplus as the most serious environmentally detrimental input for Dutch dairy farms and which is shown to have been brought about by the application of manure and chemical fertilisers. In this case, nitrogen efficiency (which is known as environmental efficiency), is estimated to be 44% on average. This means that 66% of nitrogen can be reduced without affecting output. However, this treatment of nutrient balance as an input in the production frontier framework causes mathematical violation of the DEA solution
(Coelli et al. 2007).
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Coelli et al. (2007) proposed the use of the material balance principle based on standard cost minimization. This study focuses on both cost minimization and nitrogen or nutrient minimization, in which the nitrogen or nutrients are contained in inputs.
Unlike the previous approaches, this method does not require incorporating additional inputs or outputs in production frontiers. However some shortcomings - such as the lack of universal acceptance of weights for various materials and the ambiguous treatment of immaterial inputs – have been identified. These two limitations can be overcome by the use of cumulative exergy content (Hoang and Rao, 2010).
Regarding measurement of nutrient and environmental efficiencies, an innovative approach is proposed by Coelli et al. (2007). This is based on the material balance-based model (MBM). Lauwers (2009) indicates that the MBM bridges the gap between the conventional concepts of production efficiency and eco-efficiency. Compared to the environmentally adjusted production efficiency models, the MBM is not in conflict with fundamental thermodynamic laws. In comparison to the frontier eco-efficiency models, the MBM makes its economic and environmental outcomes equally explicit (Lauwers,
2009). Additionally, Hoang & Nguyen (2013) employed both DEA and SFA techniques with the application of the MBM to examine environmental efficiency and its determinants for rice production .
3.5.6 Nutrient efficiency
Nutrient efficiency is one direct application of the materials-based efficiency models in which only several nutrients such as nitrogen and phosphorous are considered.
This is in response to the fact that the excessive use of these two nutrients are known as
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two major causes of eutrophication (Smith et al., 2006). Using the application of the materials balance principle, Hoang & Nguyen (2013) propose that because of the aggregation of nitrogen and phosphorus contaminated in the environment due to rice production they should be key elements for examining materials-based environmental efficiency. In this study, nutrient efficiency is defined as the potential reduction in the amount of nutrients that each DMU can achieve without reducing its output.
Interestingly, the nutrient efficiency can also be decomposed into two terms: technical efficiency and nutrient allocative efficiency. Technical efficiency refers to potential reductions in the use of conventional input factors such as land, labour, and chemicals.
The nutrient allocative efficiency refers to the potential for reducing the use of nutrients contained in different compounds contained in chemical fertilisers, organic fertilisers, and even in the top layer of soil. This type of analysis is particularly useful in analysing the trade-off between cost efficiency and environmental efficiency as both measures of efficiency are based on the farm cost frontier framework. A search of the literature indicates that there is no empirical investigation into the environmental efficiency of
Vietnamese coffee production, notwithstanding the fact that the overuse of chemical fertilisers has been identified as a critically important issue (Dzung et al., 2011).
3.5.7 Irrigation water efficiency
Irrigation water efficiency is measured as the minimum possible amount of irrigation water used to produce a given level of outputs. Where a potential reduction in irrigation water can be achieved without adversely affecting yields, this indicates excessive use of irrigation water (Lilienfeld & Asmild, 2007; Speelman et al., 2008;
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Varghese et al., 2013). Over-irrigation of coffee producing land has been demonstrated by a number of studies (D’haeze et al. 2003; Kuit et al. 2013). This study finds that in
Vietnam, larger farms and farms with younger operators are more likely to be characterised by efficient use of water. Notably, irrigation water efficiency is low in tomato, melon and pepper production, in spite of the government’s subsidies for water- saving technologies. It is clear that production technology and irrigation systems can help farmers improve the level of irrigation water efficiency (Wang, 2010). For example it has been shown that farmers who received greater exposure to extension services (i.e., technical training, water conservation, and the use of fertigation) tended to achieve a higher level of irrigation water use efficiency (Frija et al., 2009).
In this study of Vietnamese coffee producers the calculation of irrigation water efficiency is by way of the DEA technique rather than the SFA. Lilienfeld & Asmild
(2007) provide an example of relative irrigation water inefficiency in agricultural production employing the sub-vector DEA measurement approach (also see: Speelman et al., 2008; Frija et al., 2009; Varghese et al., 2013). These studies examine the reduction potential of irrigation water alone, based on the input-oriented efficiency model. In addition, sub-vector DEA efficiency is also employed to estimate irrigation water use efficiency in horticultural greenhouses. Variations of the irrigation water use efficiency can be analysed using a Tobit regression model. Wang (2010) used the same approach to investigate the irrigation water efficiency of farmers in north-western China.
Overall the DEA is preferred to SFA due to its flexibility in calculating sub-vector efficiencies (Speelman et al., 2008; Varghese et al., 2013).
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Socio-economic industry profile
4.1 Introduction
Economic literature has indicated that socio-economic characteristics play an important role for the development of a wide range of industries. In small scale coffee farming, factors including ethnicity, education, age, and gender have been shown to have a significant effect on management behaviour of households (Ho et al., 2014;
Wollni and Brümmer, 2012). Investigating the socio-economic characteristics of the coffee farming sector can provide useful information on the issues facing the sector and industry characteristics. This is important for both researchers and practitioners when examining practical issues faced by in coffee farmers and building up their management expertise.
Despite the significant contribution to the Vietnamese economy, people’s livelihood and the global coffee market, the coffee farming sector faces many challenges. However, socio-economic information on coffee farmers and their families is lacking in the literature. Clearly, in the development of farming programs and policies, socio-economic profiles of the target groups can provide essential background.
Previous studies have identified a number of serious problems facing the coffee farming sector and in particular heavy dependence on chemical fertilisers and overuse of irrigation water (Amarasinghe et al., 2015; D’haeze et al., 2005b). Moreover there is little information regarding the current situation in terms of to what extent there has been a change in the overuse of these inputs.
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The aim of this Chapter is to develop a current socio-economic profile of the
Vietnamese coffee farming sector and an up to date analysis of production, costs, profitability and income of coffee growers. This study seeks to answer following research questions: What are the key elements of a socio-demographic profile of
Vietnamese coffee farmers? What are the main factors influencing coffee production in
Vietnam? Do economic and environmental factors, such as chemical fertilisers and irrigation water, have an important influence on Vietnam’s coffee production?
The data used in this study comes from a recent coffee farming survey, conducted from September 2015 to January 20167. To our best knowledge, this is one of the largest surveys carried out of Vietnamese coffee farming households in the Central Highlands providing a wide range of information. The main method used in this Chapter is the descriptive approach which provides the key features of the socio-economic profile and main factors affecting production.
4.2 Demographic characteristics
The demographic characteristics of the 896 surveyed coffee farmers were categorised according to the three-major coffee growing provinces in Vietnam, namely
7 There are two datasets used in this thesis, although this socio-economic profile and economics of coffee farming was developed using the recent and largest dataset, as described in Section 3.4.2. The survey was undertaken among coffee farmer from three largest coffee growing provinces in Vietnam, namely Dak Lak, Lam Dong and Gia Lai.
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Dak Lak, Lam Dong and Gia Lai. Information includes age of the household head, family size and ethnicity.
Table 4.1: Demographic characteristics of surveyed coffee farmers Demographic characteristics Dak Lak Lam Dong Gia Lai Total Number of farms 328 348 220 896 Age of the household head (years) Mean 49.91 46.87 48.34 48.34 St. dev. 9.51 11.86 9.53 10.56 Min 20 20 23 20 Max 79 80 74 80 Family size (persons) Mean 4.71 4.43 4.45 4.54 St. dev. 1.52 1.55 1.37 1.50 Min 2 1 1 1 Max 11 11 10 11 Ethnicity Kinh 72.87% 92.73% 84.20% 82.14% Others 27.13% 7.27% 15.80% 17.86%
The age of coffee growers ranged from 20 to 80 years with an average of 48.34.
There is no significant difference in the age of coffee farmers across the three provinces.
Coffee farmers in Dak Lak were slightly older than the farmers in the other provinces, while farms from Lam Dong were the youngest on average - 46.87 years (Table 4.1).
Across the three provinces, the majority of coffee farmers were aged between 40 to 50 years. The second largest group of household heads were aged between 50 to 60 years.
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Nearly 30% of the total sample were aged under 30, while about 70 household heads
(8% of the sampled coffee growers) were aged over 60 (Figure 4.4).
Figure 4.1: Distribution of household head ages
In developing countries such as Vietnam, the size of a family is usually associated with the size of its available labour force. Thus in the coffee farming sector the family is the main source of labour and provides a useful insight into the labour availability for harvesting and irrigating. The household composition of all sampled coffee growers indicated they were composed of an average of 4.54 people which was roughly similar across the three provinces. Dak Lak had the largest average family size of 4.71 people, while Gia Lai and Lam Dong have slightly smaller family sizes of 4.43 and 4.45 people.
The majority of households - 60.2% - had a family size ranked between 3 and 5 people.
4% had families greater than 7 people, while almost 20% had small families less than or equal to 3 people
(Figure 4.2).
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Figure 4.2: Family size distribution
In terms of ethnic diversity, the surveyed area of the Central Highlands is known as the country’s most diverse region. The dominant group of coffee farmers is the Kinh group accounting for 82.14%. The rest of the surveyed participants belong to the Ede,
Tay, Nung, K’ho or M’nong groups. 27.13% of the farmers in Dak Lak were ethnic minority people as were 15.80% and 7.27% in in Gia Lai and Lam Dong provinces respectively (Table 4.1).
Figure 4.3 shows the educational attainment levels of household heads. There were eight education categories8 comprising of no education attainment, primary school not finished, primary school finished, secondary school not finished, secondary school finished, high school not finished, high school finished, and more advanced education attainment. In general, the sample had quite low education backgrounds with a majority not finishing high school. Lam Dong had the lowest education level, with the highest proportion not finishing secondary school. In Dak Lak and Gia Lai, the largest group of coffee farmers were those who had not progressed past finishing the secondary school
(Figure 4.3).
8 The current education system in Vietnam defines that primary school level is from year 1 to year 5, secondary school level is from year 6 to year 9, high school level is from year 10 to year 12 and more advanced level includes vocational trainings, higher education and graduate levels. ______Chapter 4: Socio-economic industry profile
Figur e 4.3: Educ ation level s of the hous ehol d heads
4.3 Economic profile of coffee farming
Table 4.2 presents an economic profile of coffee farming derived from 1,934 survey observations. This includes production factors, financial performance measures and direct production costs. Of the sampled farmers 52% participated in sustainability certification schemes, i.e., Utz-certified and 4C (also see Section 2.3). Regarding production factors, the average coffee yield was 3.07 tons of dried coffee beans per ha.
Other physical inputs are described and summarised in Table 4.2. It is important to note that coffee farmers do not pay usage fees for extracting water for irrigation purposes.
Thus, irrigation costs are only composed of the associated labour, fuel, electricity and irrigation facilities. These are therefore captured in family labour, hired labour and irrigation costs.
If family labour, land and coffee tree depreciation costs are excluded, the survey shows that coffee growers generally made a profit from their farms which averaged 1.5 hectares in size. The net income (the difference between gross income and direct ______Chapter 4: Socio-economic industry profile
production costs) averaged 80.11 million VND per hectare. The total direct production cost was 39.83 million VND per hectare. This includes the costs of hired labour, NPK fertilisers, other chemical fertilisers, organic fertilisers, irrigation (i.e., fuel and electricity costs), pesticides, herbicides, fungicides and machinery.
Table 4.2: Descriptive statistics of economic profile (measured in million VND per ha) St. Statistic Measure Mean dev. Min Max Certification % 0.52 0.50 0.00 1.00 Physical production factors Coffee yield ton per ha 3.07 0.99 0.50 7.00 Area per farm ha 1.59 1.18 0.20 13.00 Family labour man-days 213.54 90.91 0.00 450.00 Hired labour man-days 49.17 49.30 0.00 300.00 Chemical fertilisers tons 2.43 1.18 0.00 11.40 Irrigation water m3 1.16 0.50 0.03 5.28 Financial performance measures million VND per Gross income ha 117.97 41.03 0.00 250.00 million VND per Net income ha 79.10 38.04 -67.90 170.24 Production costs million VND per Direct production cost ha 38.87 17.47 5.05 148.98 million VND per Hired labour cost ha 7.35 7.56 0.00 60.00 million VND per Chemical fertiliser cost ha 22.25 10.50 0.00 86.67
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million VND per Organic fertiliser cost ha 4.25 6.41 0.00 92.19 million VND per Irrigation cost ha 3.39 3.39 0.04 44.00 million VND per Pesticide cost ha 0.81 0.90 0.00 9.19 million VND per Machinery cost ha 0.83 1.27 0.00 23.00
Among the production cost components, that of chemical fertiliser was the predominant one. On average, the cost was 22.25 million VND per ha, accounting for about 56% of total direct costs. The second largest cost component was hired labour equating to an average of 7.76 million VND per ha. As noted, the irrigation cost only includes fuel and electricity costs. Irrigation activities also require a large amount of labour which is included in the labour input components (i.e., family labour and hired labour).
Table 4.3 presents production factors, income and production cost breakdowns of average coffee production per hectare for the three provinces and three crop years. In terms of production scale, the average coffee farms in Lam Dong were the largest followed by those in Gia Lai and Dak Lak. However, farmers in Gia Lai and Dak Lak achieved markedly higher yields than those in Lam Dong. The use of key inputs also varied significantly between provinces but not over crop years. In particular, coffee farmers in Gia Lai tended to use more labour and chemical fertilisers than those in the other two provinces on average.
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Province Dak Lak Gia Lai Lam Dong Year 2012 2013 2014 2012 2013 2014 2012 2013 2014 Physical production factors Coffee yield (ton/ha) 3.14 3.18 3.03 3.74 3.71 3.69 2.62 2.67 2.74 Area per farm (ha) 1.16 1.17 1.18 1.62 1.73 1.76 2.06 2.03 2.04 Family labour (man-days) 209.23 209.38 208.05 250.40 247.13 243.00 198.68 202.69 202.36 Hired labour (man-days) 35.82 36.79 38.32 82.11 82.06 79.43 44.76 45.81 49.41 Chemical fertilisers (tons) 2.09 2.20 2.15 2.83 2.84 2.80 2.45 2.58 2.63 Irrigation water (m3) 1.31 1.30 1.32 1.24 1.21 1.24 0.96 0.93 0.94 Financial performance measures (million VND per hectare) Gross income 120.89 122.71 113.48 144.65 144.72 139.88 102.36 101.07 106.12 Net income 87.63 88.59 78.43 95.12 94.51 87.51 65.54 63.39 66.08 Production cost breakdowns (million VND per hectare) Total direct production cost 33.25 34.13 35.05 49.54 50.21 52.37 36.82 37.68 40.04 100% 100% 100% 100% 100% 100% 100% 100% 100% Hired labour cost 4.96 5.34 5.71 12.10 12.32 11.91 6.58 7.08 7.96 15% 16% 16% 24% 25% 23% 18% 19% 20% Chemical fertiliser cost 19.59 20.49 20.30 24.83 25.45 25.97 22.27 23.10 23.96 59% 60% 58% 50% 51% 50% 60% 61% 60% Organic fertiliser cost 3.62 3.13 3.85 7.76 7.56 9.10 2.93 2.71 3.38 11% 9% 11% 16% 15% 17% 8% 7% 8% Irrigation cost 3.64 3.63 3.67 3.49 3.34 3.85 3.16 2.93 2.83 11% 11% 10% 7% 7% 7% 9% 8% 7% Pesticide cost 0.61 0.61 0.67 0.86 0.89 1.01 0.93 0.93 1.01 2% 2% 2% 2% 2% 2% 3% 2% 3% Machinery cost 0.84 0.93 0.85 0.49 0.65 0.53 0.93 0.93 0.89 3% 3% 2% 1% 1% 1% 3% 2% 2% Table 4.3: Economic profile of coffee production over crop years
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An examination of the total direct costs of coffee production in the three surveyed crop years in the three provinces indicates a modest variation over time and over different geographical locations. On average, the total direct cost of coffee farming slightly increased over the three crop years in all provinces. Figure 4.4 also shows that farmers in Gia Lai were likely to shoulder the highest direct production cost level, although those in Dak Lak and Lam Dong faced has only slightly lower direct production costs. The variation in this cost between certified and non-certified farms in
Gia Lai and Lam
Dong
provinces was larger than that in Dak Lak (Figure 4.4).
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Figure 4.4: Direct production cost per ha in million VND (excluding family labour cost)
In terms of irrigation water, the sampled coffee farmers in Dak Lak and Gia Lai clearly consume more water than those in Lam Dong (also see Figure 4.5). Given irrigation demands large inputs of labour energy, the amount of irrigation water is positively associated with labour and irrigation cost. Thus coffee farmers in Lam Dong used less labour and spent less on irrigation. On the other hand, water extraction may negatively affect environment and soil quality. Thus, the irrigation factor involves in both economic and environmental issues.
In terms of financial performance, both gross average income and average net income tended to decrease over time for Dak Lak and Gia Lai, contrasting with a slight increase for Lam Dong. Average direct production cost per hectare increased in all provinces over the three crop years which explains the decrease in net income for coffee farmers over time for Dak Lak and Gai Lai.
Table 4.3 also sets out the production cost structure and changes in cost components over the three crop years in the three provinces. Overall the structure of coffee production cost predictably changed little over the limited time frame of three crop years. There were nevertheless some differences in cost components among the three provinces. The average coffee farmer in Dak Lak had a lower proportion of hired labour cost than those in Lam Dong and Gia Lai. Overall, coffee farmers demanded slightly more hired labour over time which on average accounted for about 15%, 25% and 20% of total direct costs for farmers in Dak Lak, Gia Lai and Lam Dong respectively.
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It is clear that coffee farmers in the three provinces used different proportions of inorganic and organic fertilisers. Note that the predominant production input, chemical fertilisers, stayed stable over time within a province, although it varied across different provinces. The sampled coffee farmers in Dak Lak and Lam Dong used a higher proportion of chemical fertilisers (i.e., about 60% of total direct costs on average) than those in Gia Lai (i.e., about 50% of total direct cost on average). In contrast, the sampled coffee farmers in Gia Lai applied more organic fertilisers in terms of both absolute values and proportion (the proportion varying over time between 15% and 17%) than those in the other two provinces (where the proportion over time varied from 7% to 9% in Lam Dong and from 10% to 12% in Dak Lak). Generally, over the three crop years, coffee farmers tended to increase the proportion of organic fertilisers in their cost structure.
The components making up the rest of the costs which included irrigation, pesticides, and machinery, remained stable over the three crop years within each province. The irrigation cost, which is composed of fuel and electricity for water- pumping, was the highest for farmers in Dak Lak (11% of total average direct costs) and averaged only 7% for the other two provinces. The other two cost items, pesticide and machinery, accounted for only between 3% and 5% of the direct production costs in all provinces and across the three crop years.
Table 4.4 provides a snapshot comparison between the sampled certified and non- certified farms with respect to coffee production factors, financial performance indicators and production cost breakdowns. As indicated in the last two columns of
Table 4.4, overall, the sampled certified coffee farms had a larger production scale than
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the non-certified farms. The results indicate that sustainability certified farms achieved higher coffee yield and were more intensive in the use of inputs (i.e., land, fertilisers, irrigation water) than the non-certified farms. As a result, certified coffee farms achieved a better financial outcome (i.e., gross income and net income from coffee production) than those of non-certified farms.
It is apparent from the survey that coffee production in Vietnam is heavily dependent on chemical fertilisers. For both non-certified and certified farms chemical fertiliser costs accounted for 63% and 52% of total direct production costs respectively.
Further examination of the data indicates that in all provinces use of chemical fertilisers in certified farms accounted a significantly lower proportion of total costs that non- certified farms. In monetary terms certified farmers in all three all three provinces spent slightly less on chemical fertilisers than their non-certified counterparts. However, certified farms in Lam Dong and Dak Lak used a marginally greater volume of chemical fertilisers than non-certified farms while in Gia Lay slightly less was used. Overall then, although there was no significant difference in the volume of chemical fertilisers used between the certified and non-certified farms, in terms of percentage of overall costs certified farms were measurably less dependent on chemical fertilisers than the non- certified farms.
Regarding the use of organic fertilisers, the variety of organic fertilisers used by surveyed farmers differed considerably in terms of weight, nutrient content and unit cost. Therefore, we used the organic fertiliser cost as an aggregated organic fertiliser index, instead of a physical factor of production. Generally, certified coffee farms
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consumed more organic fertilisers (i.e., had a higher organic fertiliser cost) than non- certified farms, except for those in Lam Dong.
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Table 4.4: Economic profile of non-certified vs certified farms
Dak Lak Gia Lai Lam Dong Total Non- Non- Non- Non- Certified Certified Certified Certified certified certified certified certified Physical production factors Coffee yield (ton/ha) 3.12 3.11 3.21 3.84 *** 2.76 2.52 *** 2.95 3.19 *** Area per farm (ha) 1.05 1.28 *** 1.37 1.79 *** 1.79 2.52 *** 1.44 1.74 *** Family labour (man-days) 224.07 195.52 *** 295.36 234.18 *** 215.47 174.59 *** 225.8 202.06 *** Hired labour (man-days) 28.43 44.51 *** 74.39 82.93 35.28 68.1 *** 35.62 61.85 *** Chemical fertiliser (tons) 2.14 2.15 3.07 2.76 2.47 2.72 ** 2.38 2.47 * Irrigation water (m3) 1.21 1.40 *** 1.20 1.24 0.99 0.86 *** 1.10 1.22 *** Financial performance measures (million VND per hectare) Gross income 117.49 120.28 125.14 147.68 *** 104.03 101.67 111.54 123.99 *** Net income 86.19 83.62 80.27 95.43 *** 66.51 62.21 76.05 81.95 *** Production cost breakdowns (million VND per hectare) Total direct production cost 31.31 36.65 *** 44.87 52.25 *** 37.52 39.46 35.48 42.04 *** 100% 100% 100% 100% 100% 100% 100% 100% Hired labour cost 4.07 6.45 *** 11.25 12.33 5.42 10.58 *** 5.33 9.23 *** 13% 18% 25% 24% 14% 27% 15% 22%
Chemical fertiliser cost 20.69 19.63 *** 25.71 25.36 23.36 22.67 22.42 22.10 66% 54% 57% 48% 62% 58% 63% 52% Organic fertiliser cost 2.58 4.38 *** 3.91 9.25 *** 3.36 2.36 *** 3.07 5.35 *** 8% 12% 9% 18% 9% 6% 9% 13% Irrigation cost 2.7 4.48 *** 2.86 3.75 ** 3.31 2.34 *** 3.01 3.74 *** 9%12%6%7%9%6%8%9% Pesticide cost 0.51 0.74 *** 0.89 0.93 1.10 0.71 *** 0.83 0.79 2% 2% 2% 2% 3% 2% 2% 2% Machinery cost 0.76 0.97 *** 0.25 0.64 *** 0.98 0.80 * 0.82 0.83 2% 3% 1% 1% 3% 2% 2% 2% Pair wise t-tests were performed. ***, ** and * refer the 99%, 95% and 90% significance level respectively.
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In terms of the use of irrigation water and its cost, the differential effect between certified and non-certified farming is unclear (see Figure 4.5) If only this single indicator is used to examine the effect of certification schemes, the result should be interpreted with caution. There was considerable variation from province to province in terms of both water consumption and cost. Certified farms in Dak Lak tended to consume more irrigation water than the non-certified farms while in Lam Dong, certified farms used less than non-certified farms and Gia Lai the difference was not significant. Figure 4.5 also indicates that the difference in the volume of irrigation water used between crop years in a province was not particularly marked, although location of farms within a province may be an important factor affecting irrigation water consumption.
Figu re 4.5: Irrig atio n wate r per ha (measured in m3) In terms of overall cost, it is clear that certified farms have a higher level that non- certified farms. That reflects generally higher costs for labour (i.e. greater use of family labour), irrigation and organic fertiliser costs (the exception being for non-certified farmers from Lam Dong who, on average, had lower costs than their certified
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counterparts for both organic fertiliser and irrigation). The cost of pesticides and machinery accounted for only a small proportion of total production cost, although some of these are statistically different between the certified farms and non-certified farms.
4.4 Conclusion
The aim of this chapter was to develop a socio-economic profile of the Vietnamese coffee farming industry. We used a descriptive approach to investigate data from one of the largest surveys made of coffee farming in Vietnam. The result provides a broad array of primary information on the socio-economic characteristics of Vietnamese coffee farmers.
This socio-demographic profile offers information on age, family size, ethnicity and education of the household heads. The findings indicate that ages of the coffee farmers are distributed between 20 and 80 years. Most are aged between 40 and 50 years, with an average of 48 years. The family size of households averaged 4.54 people while the majority of households - 60% - were between 3 and 5 people. 82% were from the Kinh group, the majority ethnic group in Vietnam. The rest belonged to variety of other ethnic groups such as Ede, K’ho, Tay, Nung and M’nong. Household heads’ education usually did not reach secondary school completion.
The economic profile of coffee farming in Vietnam provides information on farming scale, main production factors and the resulting issues facing the farming industry. Coffee farming in Vietnam is typically small-scale heavily dependent on chemical fertilisers. Given coffee is an irrigation water intensive crop a number of issues arise relating to indirect economic cost burdens and in particular those relating to
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environmental degradation. In dealing with these concerns, some half of the sampled coffee farms participated in sustainability certification schemes.
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Diversification and Productive Efficiency9
Chapter 5 offers answers for following questions, (1) What are technical efficiency level of coffee production; (2) Given different farming systems, monoculture, segregation and synchronisation, which farming systems are efficient? and (3) What are possible reasons explaining the existence of efficient systems, i.e., presence of agronomic benefits, and inefficient systems, i.e., food security?
5.1 Introduction
Coffee production is one of the primary economic sectors in the Central Highlands region of Vietnam with nearly 96% of Vietnam’s export of coffee coming from this region. Due to significant price increases in the early 1990s, the area used for coffee cultivation increased by approximately 400% from 1999 to 2000. This expansion appears to be a natural adaptation of farmers in response to past increases in prices.
However in subsequent periods the resulting increases in market supply caused prices to drop to a level which, by 2001, was lower than the production cost (Marsh, 2007). This forced many coffee farmers into bankruptcy (Wollni & Zeller 2007) and is seen as one of the reasons motivating coffee farmers to diversify their business and for the presence of several distinct farming systems in Vietnam.
In this study, we consider three typical coffee growing systems in Vietnam: mono- cropping, synchronization and segregation. The nature of specialization and
9 This chapter has been published in Economic Analysis and Policy, which can be found at http://dx.doi.org/10.1016/j.eap.2017.09.002. Only minor changes/ edits have been done.
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diversification vary significantly across these three distinct systems. Mono-cropping farms have only one land plot and grows only coffee. Segregated farming systems have more than one plot of land with each plot growing one primary type of crop. For example, where farms have two plots, one plot grows coffee and another plot grows rice.
Synchronized farming systems grow coffee together with other industrial crops in one plot and rice in a separate plot(s). There is an obvious need to know which farming system are most efficient for coffee farmers in Vietnam - an issue which the existing literature provides no empirical evidence. This literature gap is, therefore, the primary motivation of the present chapter.
It is noted that diversified systems, particularly through crops diversification, may obtain higher yields and/or cause less environmental damage (Letourneau et al., 2011).
This is known as complementary or synergy effects among crops sharing the same environment. However, there may be diseconomies of scope or negative effects of synergy as empirically observed in, for example, Coelli and Fleming (2004). Since appropriate crop diversification strategies can deliver positive effects of synthesis, it could be expected that coffee farmers would be motivated to diversify by growing industrial crops such as pepper or durian which may also mitigate market risk. However, it becomes less clear why coffee farmers have chosen the segregated system in which rice and coffee are grown in separate land plots given it does not deliver positive synthesis effects and could produce diseconomies of scope (Villano, et al., 2010). More particularly, some studies have hypothesized that Vietnamese coffee farmers diversify to rice because of the insecurity created by low incomes and volatile market conditions
(i.e., Dang 2003). If this is true, segregated farms face a trade-off between productive
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efficiency and income or poverty risks. In this chapter, we aim to provide empirical evidence on this trade-off hypothesis. Our empirical results are therefore designed to indicate the rationale for Vietnamese farmers’ decisions over which crops to grow rather than accepting that they may be made on ad hoc or irrational basis (Dang &
Shively, 2008). As such, this study can provide a useful guide for policy makers in raising the productivity of Vietnamese coffee farmers.
We utilize several techniques to examine differences in the level of productive efficiency among the three farming systems using a dataset of 167 farms surveyed in five Central Highlands communes in 2012. The input distance function is used to estimate efficiency scores for each farm. Parametric and non-parametric tests are then applied to assess if these differences are statistically different across the farming systems of the three districts. Additionally, the input distance function allows us to examine economies of diversification which is based on the concept of economies of scope in diversified farms (Baumol et al., 1988; Willig, 1979). While there are several approaches to measuring scope economies (Chavas and Di Falco, 2012; Chavas, 2011;
Ofori-Bah and Asafu-Adjaye, 2011; Chavas and Kim, 2010; Hajargasht et al., 2006), we use Coelli and Fleming's (2004) model as it does not require price information and provides a more straightforward interpretation of both efficiency results and diversification economies of each pair of crops.
The remaining part of this chapter is set out in eight sections. Section 4.2 provides a literature review. Section 4.3 provides a measure of economies of diversification using the distance function. Section 4.4 sets out the empirical models, data sources and the use of relevant variables. Survey and descriptive statistics are presented in Section 4.5.
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Section 4.6 provides the empirical results. Section 4.7 discusses the presence of agronomic benefits and the way in which they are translated into efficiency improvements and provides an explanation of why coffee farmers still choose rice.
Section 8 sets out the conclusions, policy recommendations and avenues for further study.
5.2 Literature review
The various dimensions of farming management practices are well captured in the literature (Bell and Moore 2012). In particular the farming system in which crops use the same resources, i.e., water and nutrients simultaneously, is known as an intercropping system or synchronization (van Asten et al., 2011). Another common farming integration system is crop rotation: however, it is not applicable to perennials such as coffee and other industrial crops. In addition, segregated systems are known as integration of spatially separated crops. This farming practice is found to be attractive to smallholder farmers cultivating both subsistence crops and cash crops (Solís et al.,
2009). For example, in the Central Highlands of Vietnam, coffee is a dominant crop and farming is mostly small scale (Luong and Tauer, 2006) mixed with some diversified subsistence crops, i.e., rice (Doutriaux et al., 2008). Therefore, by examining the economic benefits of different farming practices, i.e., crop specialization (not integrated organizationally), segregation (only integrated organizationally) and synchronization
(integrated organizationally and spatially and temporally) (Bell and Moore, 2012), it is intended to make a useful contribution to the farming management literature.
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Crop diversification in synchronized systems has, on the one hand, the potential to deliver agronomic and ecological benefits; however realizing these potential benefits depends on the characteristics of ecosystems and the choice of crops (Bacon 2005; Dang and Shively 2008). On the other hand, there are little or no agronomic benefits from crop segregation, although this type of farming system may have other desirable outcomes in terms of food security and allocation of inputs (Bell and Moore, 2012).
There is a rich literature on various synchronized systems of crop diversification
(i.e., Rahman 2009; Kim et al. 2012), but only a few studies examine coffee farming
(i.e., van Asten et al. 2011) and no study compares the productive efficiency between synchronized and segregated systems. For synchronized systems, it can be expected there will be a direct transformation of agronomic and ecological benefits into economic benefits through reductions in consumption of inputs without sacrificing output levels or through increasing output levels without requiring more input consumption. For example, the agronomic literature has identified crops such as avocados and fruit trees as being suitable for cultivation with coffee (Borkhataria et al., 2012) joint-production of which can result in less fertilizer being required. It is noted that lower fertilizer consumption delivers both a cost reduction and a reduction in negative environmental impacts. But synchronized systems may require greater management attention (Bell and
Moore, 2012). However, growing different crops in different land plots in segregated systems may not deliver benefits of synchronization and in many situations segregation exposes farms to a higher risk of productive inefficiency. This comes about through misallocation of resources as farmers maybe inefficient in allocating limited resources among different plots growing different types of crops (Bell and Moore, 2012).
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Although benefits of diversification are often highlighted in the literature, evaluating these benefits in economic terms is not straightforward. One reason is that a relationship between agronomic or ecological benefits and monetary benefits is not straightforward because of the diversity of impacts of input and output prices on monetary outcomes accrued to farmers, consumers and society as a whole. However, it can reasonably be expected that there is a direct transformation of agronomic benefits into improvements in productive efficiency. Therefore, we focus on this direct transformation and use these efficiency changes to quantify the impacts of diversification in coffee growing.
Coelli & Fleming (2004) suggest that diversification economies derived from an extra unit of one output can be measured by increases the marginal efficiency level of producing an extra unit of another output, holding other variables constant. This increase in marginal efficiency is due to deflating the amount of inputs to the extent that it puts the observed farm closer to the production frontier. The existence of diversification economies, therefore, implies that joint production of two outputs can improve the productive efficiency in comparison to the situation where there is separate production of two specialized outputs. An empirical study employing the input distance function by
Coelli & Fleming (2004) is based on a small panel data set of 18 coffee smallholders collected in 1992 and 1993 in six villages in Papua New Guinea. They examine diversification economies of pairs of crops, i.e., coffee and subsistence food, coffee and cash food and subsistence and cash food production. The authors report weak empirical evidence of diversification economies between coffee and subsistence food production.
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As well, diseconomies of diversification from the combination of coffee and cash food production are identified, implying a negative impact of diversification on efficiency.
Vedenov et al. (2007) uses a data set of 24 coffee-producing districts in Mexico covering the period 1997 to 2002 employing the input distance function approach to estimate technical efficiency of the districts. The authors use Coelli & Fleming’s (2004) method of measurement to examine economies of diversification for three different pairs of crops (coffee-corn, coffee-other cash crops and corn-other cash crops). However, their calculations of diversification (dis)economies are not reliable given inappropriate use of the derivation formulae (see discussion in Section 3). Our literature review finds two empirical studies - that of Coelli & Fleming (2004) and Vedenov et al. (2007) - which focus on measuring diversification economies in coffee production. However, they do not offer a comparative analysis of differing farming systems.
Empirical analysis comparing efficiency of differing farming systems is particularly important in the context of coffee production in Vietnam. Coffee growing is the primary economic activity in the Highlands region of Vietnam, where most coffee is produced. In response to favorable coffee prices in the early 1990s, farmers increased cultivation of coffee leading to increased supply and downward pressure on coffee prices. Coffee farmers, then appear to have to diversify into rice cultivation and other industrial crops. To-date, there are three distinct farming systems for small farmers in the Highland regions of Vietnam: mono-cropping, synchronization and segregation.
However there are few empirical studies on the productive efficiency of coffee farming in Vietnam (Garcia & Shively, 2011; Cheesman & Bennett, 2008) none of which compare efficiency across the different types of farming systems.
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In summary, we identify two important gaps in the empirical literature on coffee farming. First, there is no empirical study examining the efficiency effects brought by different diversification strategies of coffee farmers (i.e. different crop mixtures such as segregation versus synchronization). Second, there is no previous efficiency study focusing on the three typical farming systems for coffee cultivation in Vietnam - the world’s second largest coffee producing country. Our study aims to fill these two gaps by empirically examining the efficiency benefits of diversification in the framework of input distance functions. In doing so we aim to provide both farmers and local agricultural extension officers new information which can lead to greater efficiency in agricultural practices.
5.3 Input distance function
The measure of diversification proposed by Coelli & Fleming (2004) in the framework of input distance function has several advantages. First, it is applicable to cases where data on input prices are not available. Second, this measure allows the derivation of complementary effects directly from the distance function. Third, an inefficiency model can also be estimated to examine factors that can explain variations in the technical efficiency across farms. Following Coelli & Fleming (2004), the input distance function is defined as:
x d(,x yD )=∈ : Ly (), 5.1 D
where L(y) refers to the set of all input vectors x that can produce the output vector y. The distance function, d(x,y), is non-decreasing in x, and non-increasing in y, and
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linearly homogeneous and concave in x. If x belongs to the input set of y (i.e., x ∈ L(y)) then the value of the distance function is equal to or greater than one (d(,xy )≥ 1). The distance is equal to unity if x belongs to the isoquant of y. That is, the firm is said to be technically efficient or inefficient if the value of the distance equals one or exceeds one respectively. Note that the value of the distance equals the inverse of the traditional input-oriented technical efficiency score proposed by Farrell (1957).
Coelli & Fleming (2004) suggest that diversification economies produced from an extra unit of output i increases the marginal effici ency level of producing an extra unit of output j, holding other variables constant. That is, the first partial derivative of the distance function with respect to the ith output is the marginal distance of producing an extra unit of the ith output. The cross derivative of the distance with respect to the ith and jth output represents the effect of change in one additional unit of the jth output on the marginal distance of producing ith output10. The existence of diversification economies implies joint production of two outputs – the ith and the jth - delivering higher input-orientated efficiency. That is, there is less input consumption with the given level
10 This is also similar to the utility theory which states the cross partial derivative of the utility function with respect to good X and good Y is positive if these two goods are complements in
∂∂∂2 ==UU > consumption (U XY 0 ). This means that consuming more of good Y increases ∂∂XY ∂ X ∂ Y the marginal utility of good X.
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of output than that of producing two outputs separately. Economies of diversification11 between two outputs is therefore observed if:
∂∂∂<=2 Dyyijq(x, y) /ij 0, , 1,...., 5.2
Note that a positive cross derivative with respect to the ith and jth output implies diseconomies of diversification12.
We also examine the absolute values of the cross derivative to infer the relative magnitudes of the diversification economies. This provides an indication of the relative effects of diversification economies when there are more than two outputs (i.e. more than one pair of two outputs i and j). More specifically, if economies of diversification are observed, the most favourable combination (i.e. largest marginal efficiency gain due to joint production) is quantified as:
11 There are both similarities and differences between the term ‘diversification economies’ used in this study and the term ‘output complementarities’ used in other studies. Villano et al. (2010) define output complementarities as a marginal increase of one output as the result of increasing the quantity of another output. However, the cross derivative of the input distance function in expression (2) with respect to the ith and jth output does not match this definition of output complementarities.
12 ∂∂∂≠∂∂∂=22 β Note that DyyD(x, y) /ij ln ( x, y) / ln yy i ln j ij. In Vedenov et al. (2007) only used interaction between only two outputs (βij) in calculating this measures while interaction term (βi βj+
βij) should be used. More details are provided upon an email request.
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∂ 2 D Max{}, i≠ j and ij,= 1.... q for the largest efficiency gain due to joint ∂∂ YYij production. 5.3
If diseconomies of diversification are observed, the combinations that have minimum negative effect on the efficiency loss due to joint production is:
∂ 2 D Min{}, i≠ j and ij,= 1.... q for the least efficiency loss due to joint ∂∂ YYij production. 5.4 Since inputs and outputs are normalized at their means, for more meaningful interpretations of the empirical results of the average farm, the expression (5.2) can be represented as13:
∂2 DD 1 Δ==D Δ= ()0ββ +< β 5.5 YYij|1∂∂ i j ij YYij YY ij 2
Theoretically, this distance D is always positive; therefore, from expression (5.5)
1 we see that ()0ββ+< β implies evidence of the diversification economies. ij2 ij
5.4 Empirical model specifications
A translog input distance function is used in this study to characterize the production technology as it is more flexible than the Cobb-Douglass functional form and does not require restrictions of rectangular hyperbola isoquants (Morrison-Paul et al.,
2000). The fully specified translog input distance function is specified as:
13 See Appendix 1 for the derivation of the cross derivative of the input distance function with respect to output i and output j.
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qqqp pp I =+αβ +11 β + α + α lnDyikkkkkkmmmmmm0'''' ln ln yyxxx ln ln ln ln kkkmmm====122 1 '1 1 == 1 '1 pq + 1 τ kmlnxy m ln k 2 mk==11 5.6 where i = 1 …. N refers to the number of firms, q and p represent the number of outputs and inputs.
According to O’Donnell & Coelli (2005), the homogeneity of degree +1 in inputs implies:
pp p αα==τ = mmm1,' 0, and km 0 5.7 mm==11 m=1
Plugging the constraints in Equation (7) into Equation (6), we have:
qqqp I =+αβ +1 β + α ln(Dxikkkkkkmm /10 ) ln y ' ln y ln y ' ln( xx / 1 ) kkkm====11'122 pp pq 5.8 ++11ατ mm'1'1ln(x m /xxx )ln( m / ) mk ln( xxy m / 1 )ln k 22mm==2'2 m == 2 k 1 ββ= αα= The symmetry requires that kk'' k k and mm'' m m .
I i i Following Coelli & Perelman (1999), the “-ln( D i )” term is set to be v - u , and re-arranging Equation 2.8 gives an input distance function as:
qqqp −=+αβ +1 β + α lnxy10kk ln kkkk ' ln yyxx ln ' m ln( m / 1 ) kkkm====11'122 pp pq 5.9 +++−11ατ mm'1'1ln(/)ln(/)x mxxx m mk ln(/)ln xxyvu m 1 k i i 22mm==2'2 m == 2 k 1
where y refers to output; vi, captures the effects of statistical noise which is