Working Papers
No. 14/2012 (80) Anna Bartczak Jürgen Meyerhoff Valuing the chances of survival of two distinct Eurasian lynx populations in Poland – do people want to keep doors open?
Warsaw 2012
Valuing the chances of survival of two distinct Eurasian lynx populations in Poland – do people want to keep doors open?
Anna Bartczak Jürgen Meyerhoff University of Warsaw Technische Universität Berlin Faculty of Economic Sciences Institute for Landscape and e-mail: [email protected] Environmental Planning
[eAbstract This survey deals with valuing the social benefits of increasing chances of survival of the two main Eurasian lynx populations in Poland: the Lowland population and the Carpathian one. The populations are exposed to different risks of extinction. Using a discrete choice experiment we examined the influence of the initial degree of endangerment of those lynx populations on respondents’ funds allocation. The results show that instead of investing in the option with the expected higher outcome a main driver of individuals’ decisions regarding the conservation of threatened species seems to be loss aversion. Thus, people seem to try to keep options (doors) open by investing more in the more vulnerable population. Moreover, employing a scale-extended latent class model allowed to detect segments among individuals showing different types of response behavior and therefore improved the accuracy of the willingness to pay estimates considerably compared to a conditional logit model.
Keywords: discrete choice models, loss aversion, Lynx conservation, scale-extended latent class model, threatened species
JEL: Q23, Q51, Q56, Q57
Acknowledgements: This study was carried out as a part of the POLFOREX project (“Forest as a public good. Evaluation of social and environmental benefits of forests in Poland to improve management efficiency.”; PL0257) funded by EEA Financial Mechanism, Norwegian Financial Mechanism and Polish Ministry of Science and Higher Education. Funding support is gratefully acknowledged.
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1. Introduction Biodiversity provides a wide array of social benefits but it also becomes more and more threatened as a result of human activities. From an economic point of view, one of the key problems associated with conservation policy decisions is that the biodiversity benefits are often not directly reflected in market prices and therefore conservation is mostly viewed as a cost burden instead of an investment in social values. However, economic sciences have developed methods that allow to estimate the economic value provided by biodiversity by using either revealed or stated preferences of individuals. Recognizing the importance of the economic value of biodiversity can improve decision-making processes and use limited public financial sources in an efficient way. Recommendations that the results of non-market valuation studies should be taken into account in designing and implementing conservation policies have been made recently by the Millennium Ecosystem Assessment (MEA, 2005) or “The Economics of Ecosystems and Biodiversity” initiative (TEEB 2010). Non-market valuation techniques and stated preferences methods have been applied to value the protection of wildlife for several decades now. Martín-López et al. (2008) reviewed sixty contingent valuation studies concerning the willingness to pay (WTP) for species conservation. Richardson and Loomis (2009) conducted a meta-study of more than forty estimates from contingent valuation studies, focusing solely on threatened and endangered species. Both reviews show that the protection of wildlife often leads to large social benefits. Recently, the application of choice experiments (CE) has become more popular to assign an economic value to wildlife conservation programs (e.g, Lew et al. 2010; Wallmo and Lew 2011, Jacobsen et al. 2012). A problem for economic valuation studies is that conservation programs are in general long-term projects and their outcome cannot be predicted with certainty. Generally, biologists have difficulties to predict an increase in the population size of an endangered species as a result of conservation measures or to give probabilities for the chances of survival of a particular species in numerical terms; the outcomes are, in other words, uncertain per se. In contrast, in most valuation surveys concerning species preservation respondents are presented “certain” outcomes, mostly an increase in the number of species by X% (see Richardson and Loomis, 2009). To incorporate the uncertain nature of conservation outcomes the present valuation study follows the International Union for Conservation of Nature (IUCN) Red list classification of threatened species to measure potential benefits of a biodiversity conservation program. It shows the gradation of species chances of survival without assigning any specific numbers or species sizes to those chances. The study, designed as a choice experiment, concerns conservation of the two main Eurasian lynx populations in Poland: the Lowland population that occupies the northeastern part of the country and the Carpathian population that is located in the south. Even though Poland is one of the few European countries where lynx populations have survived in the wild, nowadays the entire species is considered as near threatened as the result of insufficient protection programs. However, according to biologists, the two populations face different risks of extinction; the Lowland population is more endangered than the Carpathian one (von Arx et al., 2004 ). The main objectives of the present study are to investigate a) whether respondents take the initial risk levels into account when valuing the outcomes of species protection and b) whether their willingness to pay (WTP) diminishes with an increasing risk reduction, i.e., higher chances of survival. From a naive, rational perspective, one would expect that a dominant strategy for respondents answering a choice experiment would be to solely improve the changes of survival of the population that has the better initial conditions. As people
1 generally do not encounter lynx in the wild because the animals are very timid, the location of the population should not be an important motive for paying for a certain population. On the other hand, people might be afraid of losing one lynx population, and, due to aversion of loss, might try to increase the probability of survival for the population with the poorer initial conditions by “investing” more in this population. In a different context, Shin and Ariely (2004) show that people often have a tendency to keep options available. If an option is threatened to disappear, this threat brings decision makers to invest more effort and money to keep the options open. Whether this remarkable finding applies to the conservation of endangered species as well could be important information for the development of wildlife conservation programs. Additionally, this study is, to the best of our knowledge, the first one aiming to determine the value of lynx protection and the first in the Central and Eastern Europe aiming at the valuation of carnivore protection. Thus, it helps to fill a significant gap with respect to the knowledge about people’s preferences for conserving those species in this part of Europe. The remaining article is structured as follows: The next section briefly informs about lynx conservation in Poland. Section 3 then describes the applied methods and the survey design. Section 4 presents the results while Section 5 discusses these and proposes some implications for conservation policy as well as for future surveys.
2. Lynx protection in Poland The Eurasian lynx (Lynx lynx) is the third largest predator in Europe, after the brown bear and the wolf. Lynx live in forests in low density populations occupying large territories. The animals prey at night, mainly on small ungulates and hares. They avoid people and are no danger to them. Encounters between lynx and humans in the wild are highly unlikely. The current population status of the Eurasian lynx in Europe and the status of its conservation is described in detail by von Arx et al. (2004). Poland is one of the few European countries where lynx have survived in the wild. However, the number of Polish lynx living in the wild has decreased to a third over the last 20 years and is estimated to be about 180-200 individuals in total (Jędrzejewski et al. 2002; von Arx et al. 2004). Although lynx are officially protected in Poland since 1995, little has been done so far to ensure the species survival (Niedziałkowska et al. 2006). In general, their current status in Poland is considered as near threatened according to the International Union for Conservation of Nature (IUCN) Red List of threatened species. There are two main lynx populations in Poland: the Lowland population in the northeast and the Carpathian population in the south of the country. Both populations live in border regions and are part of two major populations of this species in Europe1. While the lynx is in general considered as a near threatened species in Poland nowadays, the risk of extinction is not the same for the Lowland and the Carpathian population. The Polish Carpathian population is larger in number and distribution than the Lowland one. It is estimated at about 100 animals. Existing migration corridors allow exchange of the Carpathian lynx between countries. The other lynx population – the Lowland one is estimated at about 60 animals and occupies highly fragmented habitat2. This group is more isolated from lynx populations in other countries. These factors contribute to a higher risk of extinction of
1 Apart from Poland the Carpathian Eurasian lynx population occurs in the Czech Republic, Slovakia and Ukraine, whereas the Lowland lynx population is present in Baltic and Scandinavian countries. 2 In addition to the Lowland and Carpathian lynx populations and a few isolated individuals in the north of Poland, a group of 12-15 lynx lives in central Poland in the Kampinowski National Park. The lynx were reintroduced there in 1994. This reintroduction was debated very controversial as all the animals were born in captivity. Moreover, the group is isolated and cannot survive in the wild without human support. 2 the Lowland lynx in comparison to the Carpathian population. The detail information concerning lynx occurrence in Poland has been presented inter alia by Jędrzejewski et al. (2002), Niedziałkowska et al. (2006) or Schmidt (2008). Niedziałkowska et al. (2006) identify the fragmentation of forest habitats as a major threat for the survival of the lynx populations in Poland. Over the last two decades the number of cars in Poland doubled, the motorways network has increased three times (GUS, 2011) and the country continues to face fast development of transportation infrastructure, mainly highways. As construction projects frequently neglect the need for sufficient number, size and proper location of wildlife passes across the highways this development contributes to habitat fragmentation and further isolation of source populations of large carnivores (Niedziałkowska et al., 2006). Other threats for lynx populations occur as a result of current forest management i.e., afforestation of open spaces and not leaving enough deadwood (Schmidt 2008). Such changes in forests disturb the lynx hunting and living conditions. Additionally, game hunting and poaching by humans cause food scarcity. If these impacts on habitat conditions continue, it is anticipated that Polish lynx population may be seriously threatened in the next decades (Niedziałkowska et al., 2006) .
3. Methods and survey design 3.1 Preference and scale heterogeneity The choice experiment method is based on the characteristics theory of value and assumes that any environmental good, e.g., the conservation of a threatened species, can be described in terms of its characteristics or attributes (Louviere et al. 2000). A change in forest management, and therefore in forest biodiversity, for example, can be described by different levels of harvested trees, different amounts of deadwood that remain in the forest and various constrains to forest recreation (e.g., denied access to certain areas). People making choices between different bundles of attributes express their preferences. Based on the observed choices it is possible to infer which attributes significantly influence choice, and, if one of the attributes included is a price or a cost, what people are willing to pay for changing the level of one or more attributes. Capturing heterogeneity among respondents to a CE has been an important research topic within the last decade and it is increasingly investigated whether this heterogeneity is caused by differences in taste or differences in scale variation. The multinomial logit (MNL) model assumes that respondents do not vary with respect to neither taste nor scale. Historically, efforts to overcome the limitations of the MNL model were mainly concerned with taste heterogeneity, particularly by employing the random parameter logit (RPL). In these models scale is generally normalized to one assuming that all individuals respond to the choice experiment with the same consistency, that is identical error variances. Some researchers (e.g., Louviere and Eagle 2006), however, have stressed that scale matters and might even be more important than taking taste heterogeneity into account. As a result of this strand of research Fiebig et al. (2010) as well as Greene and Hensher (2010) have operationalized models that supposedly allow taking scale heterogeneity into account. Among them are the scale heterogeneity model (S-MNL) and the generalized mixed (GMX) logit model. The latter allows identifying both taste and scale heterogeneity separately. Whether these models allow identifying the scale parameter separately is currently debated. Hess and Rose (2012) argue that the attempts presented in the literature to disentangle the two components are misguided. They find that the various model specifications presented, for example by Fiebig et al. (2010), are different parameterizations that allow for more flexible distributions but do not capture scale heterogeneity.
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An alternative approach to capture, at least partially, the effect of scale heterogeneity is to estimate scale differences among subgroups of a sample by normalizing the scale parameter in one of the groups to zero. One technique that has been applied quite often, especially in benefit transfer studies, is the grid-search procedure suggested by Swait and Louviere (2003). An alternative to this procedure is to estimate the scale parameter by using full information maximum likelihood (Campbell et al. 2008; Olson 2009). Madigson and Vermunt (2007) propose a scale extended latent class (LC) model. The basic idea behind this model is that respondents are not only allocated to a preference class but also to a variance class. In addition to taking scale differences between subgroups into account the model allows to explain both membership in a preference and in a scale class separately through specifying covariates for each membership function. Recent applications of the scale-adjusted latent class model are Campbell et al. (2011), Flynn et al. (2010) and Mueller et al. (2010). Generally, the LC approach assumes that c latent preference segments exist in the population, each with a different preference structure, and that an individual n belongs to one of the segments c (1, …., C). Membership to one of the classes, however, is unknown to the analyst. Within the random utility framework the utility function takes the following form: