Submitted by Ivan Zili´cˇ
Submitted at Department of Economics
Supervisor and First Examiner Dr. Rudolf Winter- Ebmer
Second Examiner Dr. Ren´eB¨oheim Essays in Applied September 2017 Econometrics
Doctoral Thesis to obtain the academic degree of Doctor of Philosophy in the PhD Program (Doktoratsstudium) in Economics
JOHANNES KEPLER UNIVERSITY LINZ Altenbergerstraße 69 4040 Linz, Osterreich¨ www.jku.at DVR 0093696 Statutory declaration
I hereby declare that the thesis submitted is my own unaided work, that I have not used other than the sources indicated, and that all direct and indirect sources are acknowledged as references. This printed thesis is identical with the electronic version submitted.
Ivan Žilic´
signature
place and date
2 ...zahvali Tajnom za sva dobroˇcinstva.
Tin Ujevi´c
3 4 Acknowledgments
This thesis is a result of a five-year effort and I would like to acknowledge all people who helped me along the way.
First and foremost, I would like to thank my advisor Rudolf Winter-Ebmer as I benefited greatly from his knowledge, experience, and patience. His comments, guidance and sup- port were of invaluable importance, not only for the thesis, but also for my professional development. I thank René Böheim, my co-advisor, whose sharp and constructive com- ments on early versions of papers presented in this thesis substantially improved their quality. I also thank Gerald Pruckner, a third member of my thesis comettee, who gave a beneficial input on this thesis, especially to the third chapter. I thank all the members of JKU Department of Economics, especially Katrin and Alex, for making the research process an enjoyable experience.
I thank The Institute of Economics, Zagreb where I was employed as a research assistant throughout my PhD studies. Their financial support and excellent working environment enabled me to fully devote my time to research. There I also met people who helped me during my studies, especially in the beginnings. I thank all of them, especially Marina, Iva and Rubil, for their friendship and help.
As I did my coursework in Madrid, I thank all the people I met there. To single out a few of them would not be justly, as we had a spectacular time as a group; thank you for everything. I also thank my Zagreb friends—Selma, Rafo, Cupiˇ c,´ Bruno, Vedran, Prebeg, Tiric,´ Vlado, Suljo and Maric—as´ they provided just enough distractions to keep me focused.
I thank my mom, dad, sister and her family for all the sacrifices, for always having my back and for being a true inspiration.
And finally, I thank Marina, for everything. For the help, patience, sacrifices, and support. Thank you for your love.
5 Summary
This thesis consists of three chapters. In ChapterI, Effect of forced displacement on health, I analyze health consequences of forced civilian displacement that occurred dur- ing the war in Croatia 1991-1995 which accompanied the demise of Yugoslavia. Dur- ing the Serbo-Croatian conflict a quarter of Croatian territory was ceded, 22,000 people were killed, and more than 500,000 individuals were displaced. Using the Croatian Adult Health Survey 2003 I identify the causal effect of forced migration on various dimensions of measured and self-assessed health. In order to circumvent the self-selection into dis- placement, I adopt an instrumental variable approach where civilian casualties per county are used as an instrument for displacement. I find robust adverse effects on probability of suffering hypertension, tachycardia as well as on self-assessed health and Short Form Health Survey (SF-36) health dimensions. Comparing OLS to IV estimates yields a con- clusion of a positive selection into displacement with respect to latent health. Given the likely violation of the exclusion restriction, I use a method which allows the instrument to affect health outcomes directly and conclude that, even with substantial departures from the exclusion restriction, displacement still adversely affects health.
ChapterII, General versus Vocational Education: Lessons from a Quasi-experiment in Croatia, presents a research which identifies the causal effect of an educational reform implemented in Croatia in 1975/76 and 1977/78 on educational and labor market out- comes. High-school education was split into two phases which resulted in reduced track- ing, extended general curriculum for pupils attending vocational training and attaching vocational context to general high-school programs. Exploiting the rules on elementary school entry and timing of the reform, I use a regression discontinuity design and pooled Labor Force Surveys 2000–2012 to analyze the effect of the reform on educational attain- ment and labor market outcomes. We find that the reform, on average, reduced the proba- bility of having university education, which I contribute to attaching professional context
6 to once purely academic and general high-school programs. I also observe heterogeneity of the effects across gender, as for males we find that the probability of completing high school decreased, while for the females we do not observe any adverse effects, only an increase in the probability of having some university education. We explain this hetero- geneity with different selection into schooling for males and females. The reform did not positively affect individuals’ labor market prospects; therefore, we conclude that the observed general-vocational wage differential is mainly driven by self-selection into the type of high school.
Do physicians respond to financial incentives is the research question tackeled in Chap- ter III named Do Financial Incentives Alter Physician Prescription Behavior? Evidence from Random Patient-GP Allocations. With co-author Alexander Ahammer I address this question by analyzing the prescription behavior of physicians who are allowed to dispense drugs by themselves through onsite pharmacies. Our identification strategy rests on mul- tiple pillars. First, we use an extensive array of covariates along with multi-dimensional fixed effects which account for patient and GP-level heterogeneity as well as sorting of GPs into onsite pharmacies. Second, we use a novel approach that allows us to restrict our sample to randomly allocated patient-GP matches which rules out endogenous sort- ing as well as principal-agent bargaining over prescriptions between patients and GPs. Using administrative data from Austria, we find evidence that onsite pharmacies have a small negative effect on prescriptions. Although self-dispensing GPs seem to prescribe slightly more expensive medication, this effect is absorbed by a much smaller likelihood to prescribe something at all in the first place, causing the overall effect to be negative.
7 Contents
List of Figures 11
List of Tables 12
IEffect of forced displacement on health 13
I.1 Introduction...... 13
I.2 War and displacement in Croatia...... 16
I.3 Data...... 17
I.4 Empirical strategy...... 22
I.4.1 Identification...... 25
I.5 Results...... 28
I.5.1 Sensitivity analysis...... 31
I.6 Conclusions...... 35
I.7 Appendix...... 37
II General versus Vocational Education: Lessons from a Quasi-experiment in Croatia 39
II.1 Introduction...... 39
II.2 Educational reform in Croatia...... 43
II.3 Methodology and data...... 46
II.3.1 Methodology...... 46
II.3.2 Data...... 48
8 II.3.3 Identification...... 50
II.4 Results...... 53
II.4.1 Reduced tracking and educational outcomes...... 53
II.4.2 Heterogeneous effects...... 54
II.4.3 Robustness...... 60
II.4.4 Extended general curriculum and labor market outcomes..... 62
II.5 Conclusions...... 64
III Do Financial Incentives Alter Physician Prescription Behavior? Evidence from Random Patient-GP Allocations (with Alexander Ahammer) 67
III.1 Introduction...... 67
III.2 Related literature and our contributions...... 70
III.3 Institutional setting...... 72
III.3.1 Country doctors and onsite pharmacies...... 73
III.3.2 Weekend prescriptions...... 74
III.4 Data...... 75
III.5 Methodology...... 79
III.5.1 Outcome variables...... 79
III.5.2 Identification...... 81
III.6 Results...... 84
III.6.1 Heterogeneous effects...... 92
III.7 Conclusions...... 93
9 IV Bibliography 96
10 List of Figures
1 Civilian casualties by county...... 21
2 Violation of exclusion restriction...... 34
3 Changes in high-school education in Croatia during the 1975/76 and 1977/78 reform...... 45
4 Discontinuity in the reform inclusion...... 47
5 Histogram of date of birth...... 52
6 Regression discontinuity graphs for the highest educational attainment.. 55
7 Distribution of education by gender in 2011 for 15+ individuals..... 60
8 Educational outcomes...... 61
9 Years of work...... 64
10 Heterogeneous effects for different patient age groups, weekend sample, extensive margin...... 89
11 Heterogeneous effects for different GP age groups, weekend sample, ex- tensive margin...... 90
12 Heterogeneous effects for different patient education groups, weekend sample, extensive margin...... 91
11 List of Tables
1 Descriptive statistics of health outcomes...... 20
2 First stage and falsification...... 26
3 War displacement effects...... 29
4 Sensitivity analysis...... 35
5 Summary statistics...... 37
6 War displacement effects excluding Vukovar-Syrmia County...... 38
7 Descriptive statistics...... 49
8 Effect of the reform on predetermined variables...... 50
9 Results for the highest educational attainment—males...... 58
10 Results for the highest educational attainment—females...... 59
11 Labor market outcomes...... 63
12 Descriptive statistics...... 76
13 Average per patient per year drug expenses for GPs with and without onsite pharmacies...... 84
14 Estimations results for full sample...... 85
15 Estimation results for sample of weekend and holiday prescriptions, ex- tensive margin...... 87
16 Estimation results for sample of weekend and holiday prescriptions, in- tensive margin...... 88
17 Heterogeneous effects, weekend sample...... 92
12 I.E ffect of forced displacement on health
I.1.I ntroduction
Armed conflicts, along with other dreadful consequences, cause mass civilian displace- ment. Individuals are forced to leave their homes due to imminent life threatening sit- uations that cause a series of challenges, life changes and losses. According to official UNHCR data, by the end of 2014 the number of forcefully displaced individuals was 59.5 million. In order to motivate a policy that mitigates challenges and adverse conditions that the displaced people face, it is necessary to evaluate the effects of displacement on individuals. Indeed, the literature on consequences of displacement, economic as well as medical, is gaining momentum as micro data sets become more available.
This paper contributes to this literature by analyzing health effects of civil displacement during the war in Croatia 1991-1995, which was a part of larger-scale conflicts in the 1990s that accompanied the break up of Yugoslavia. During the Serbo-Croatian conflict a quarter of Croatian territory was ceded, 22,000 people were killed, and more than 500,000 individuals were displaced, more than 10% of Croatia’s pre-war population.
While health consequences of this conflict are an important issue on its own, analyzing displacement caused by this conflict may provide broader implications. This war was set in a moderately developed country, very close to Central Europe. In particular, Croa- tia’s GDP per capita in 1990 was 8,123 international 1990 dollars - two thirds of Spain’s (Bolt and Zanden, 2014), while the distance from Croatia’s capital, Zagreb, to Vienna and Munich is less than 400 and 600 km, respectively.
Therefore, civilian displacement during the war in Croatia was different than war-induced migration in a developing country. During displacement, most of the people in Croatia were settled to private accommodation (with their relatives or in state-provided hotel and apartment accommodation) and not in refugee camps (Global IDP Database, 2004), there-
13 fore the incidence of communicable diseases, neonatal health problems, and nutritional deficiencies, although increased, was not the most important cause of death (Toole and Waldman, 1997). Therefore, analyzing health consequences of mass civilian migration in a more affluent country, apart from estimating the lower bound of the displacement effect, can offer valuable information to other situations that create mass displacement, such as natural disasters, global warming and big infrastructure projects (Sarvimäki et al., 2009).
In this paper, using the Croatian Adult Health Survey collected in 2003, we identify the causal effect of war-migration on various dimensions of measured and self-assessed health for females. Due to the potential endogeneity of the displacement status, we adopt an IV approach. To the best of our knowledge, this is the first analysis of health effects of dis- placement that accounts for self-selection. Displacement, although to a great extent a forced action, is partly a result of a decision, and observed patterns of migration during the war in Croatia, in particular, partial flight of population from war-inflicted areas and displacement of individuals who lived far from conflict, validate this claim. Given that we have limited pre-war individual characteristics, we find the assumption that displaced individuals and stayers do not differ in observed and unobserved characteristics too re- strictive. Instead, relying on the ethnic pattern of the conflict, which is orthogonal to pre-war health or health-related variables, we use civilian casualties across counties as an instrument for the displacement status, like in Kondylis(2010). As the instrument might affect health directly, we also advance the Kondylis(2010) IV approach by using union of confidence intervals from Conley et al.(2012) which enables us to make inference conclusions even if the exclusion restriction does not hold.
Results indicate that various health dimensions are adversely affected by displacement as 90% interval estimates exclude that there is no effect on the incidence of hypertension, self-assessed health, and both emotional and physical Short Form Health Survey (SF-36) dimensions. Comparing simple estimates and estimates that account for self-selection in- dicates positive self-selection into displacement with respect to latent health. These results hold for numerous robustness checks, including changing the definition of displacement,
14 changing the composition of control group as well as other sample restrictions.
While we claim that the instrument we use, civilian casualties across 21 counties in Croa- tia, is exogenously determined as the conflict distribution across counties was driven by ethnic structure, the exclusion restriction is very likely to be violated. In particular, civilian causalities, which approximate war intensity, affect health directly and not only through displacement. This concern is amplified by the existing literature, for example Kesternich et al.(2014), but also by unusually large IV estimates, which indicate that esti- mates are biased towards more adverse effects of displacement. In order to account for the likely violation of the exclusion restriction we use union of confidence interval method from Conley et al.(2012). Results of sensitivity analysis provide compelling evidence that forced displacement may have negative health consequences even with substantial departures from the exclusion restriction.
The literature on economics of forced migration is still in its early stage and it is gain- ing momentum as micro data sets on war-inflicted areas become available. Ruiz and Vargas-Silva(2013) provide an overview of the literature on the e ffect of displacement on migrating individuals as well as on hosting communities. Although numerous papers show that displacement impacts negatively the economic perspective of an individual,1 Sarvimäki et al.(2009) show that displacement might even induce higher mobility and consequently higher long-run incomes. In the health literature on displacement, there is a consensus that displacement adversely affects the health of individuals.2 For example, Porter and Haslam(2001) provide a meta analysis of papers that analyze psychological consequences of war displacement caused by the demise of former Yugoslavia, all of
1For example, Kondylis(2010), analyzing post-war Bosnia, shows that displaced males are more likely to be unemployed, while displaced females are more likely to drop out of labor force. Eder(2014), also using post-war Bosnia, shows that displaced individuals invest less in their children’s education. Bauer et al.(2013), analyzing the integration of Germans from Eastern Europe, conclude that the first generation of migrants has lower incomes and ownership rates. Fiala(2015), analyzing the displacement in Uganda, concludes that displaced households that returned had a significant drop in consumption and decline in assets. Abdel Rahim et al.(2013), studying displacement in Nuba Mountains in Sudan, conclude that displaced households hold fewer assets and are less involved in production. 2The exception being Abdel Rahim et al.(2013) who find that health status of displaced households in Nuba Mountains in Sudan actually improves due to the behavioral change (hygiene, use of mosquito nets and family planing).
15 which find mental health impairment of displaced and refugee persons. Similar results are also found on the displaced population in other war-inflicted areas, see Steel et al. (2002) and Kuwert et al.(2009). Thomas and Thomas(2004) analyzing key issues of displaced and refugee groups find that most common psychological consequences among those groups include Post Traumatic Stress Disorder (PTSD), depression, somatization and existential dilemmas.
The rest of the paper is organized as follows: section 2 provides background on war and displacement in Croatia, section 3 explains the data set used, section 4 presents the empirical strategy and discusses the identifying assumptions, section 5 gives results and relaxes the exclusion restriction while section 6 concludes the paper.
I.2.W ar and displacement in Croatia
War in Croatia 1991-1995 was part of a larger scale of conflicts on the territory of for- mer Socialist Federative Republic of Yugoslavia (SFRY) in the 1990s. While the political tensions between Croatia and the leadership of SFRY were apparent already in the 1970s and 1980s, the large-scale armed conflict escalated after Croatia’s declaration of indepen- dence in June 1991. By the end of 1991 rebel Serbian forces, with the support of Yugoslav People’s Army (YPA), controlled by Serbia, declared the unified Republic of Srpska Kra- jina, taking a quarter of Croatian territory. In 1992 YPA had withdrawn and the United Nations Protective Force (UNPROFOR), as a part of peacekeeping mission, deployed the Serb held territories. In the mid-1995 Croatian army engaged in two large-scale military operations Storm and Flash and reclaimed most of its occupied territory excluding the Eastern part of Slavonia, Baranja and the Western Sirmium which was reintegrated in 1998 under the mandate of the UN Transitional Authority for Eastern Slavonia, Baranja and Western Sirmium (UNATES).
The aftermath of the war in Croatia is as follows: estimates of total casualties are around
16 22,000 individuals,3 while the estimates for the number of refugees and internally dis- placed persons of all nationalities is more than half a million individuals, which repre- sents a significant portion of Croatia’s 4.7 million population in 1991. For example, in March 1993 there were 237,000 individuals internally displaced, while 163,000 went to seek refugee (Repac-Roknic´, 1992). Ethnic Croats were displaced mostly during the 1991 and 1992 as Serbian forces progressed, while ethnic Serbs were displaced during 1995 as Croatian forces engaged in military operations to reclaim occupied territories.4 After the recovery of occupied territories in 1995 and 1998, internally displaced Croats begun their return to their homes. For example, in May 1995 there were 210,592 internally displaced individuals, while in April 2003, at the time when the Croatian Adult Health survey was collected, around 16,000 people in Croatia were still internally displaced (Global IDP Database, 2004).
I.3.D ata
Our main source of data is the Croatian Adult Health Survey 2003 (henceforth CAHS), collected by the Ministry of Health of the Republic of Croatia with consultancy of the Canadian Society for International Health. Sampling was stratified by six geographical regions in Croatia (North, South, East, West, Central and the capital Zagreb) from which 10,766 households were randomly picked for an interview. In total, 9,070 individuals older than 18 were interviewed, which implies that the response rate was 84.3 %. Individ- uals were interviewed from March to June 2003 with the assistance of 238 visiting nurses. The survey is representative on the national as well as on the regional level. CAHS con- tains information on measured health outcomes, Short Form Health Survey (SF-36), data on the use of health infrastructure, data on eating, smoking, drinking and exercising habits as well as basic demographics, migrations and labor activities (Vuletic´ and Kern, 2005).
3Živic´ and Pokos(2004) estimate that 22,192 individuals were killed: 8,147 Croatian soldiers, 6,605 Croatian civilians and 1,218 missing persons from Croatia as well as 6,222 Serbian casualties. 4Global IDP Database(2004) reports that total of 220,000 ethnic Croats were internally displaced at the beginning of the war, while 300,000 ethnic Serbs were displaced in 1995.
17 CAHS has three particularities which make it convenient for analyzing the effect of dis- placement in Croatia. The first one is the explicit identification of individuals that mi- grated during the 1991-1995 due to the war, a desirable feature in the analysis of forced displacement (Ruiz and Vargas-Silva, 2013).
In particular, forced migrants are identified using a question: "Did you change your place of living between 1991 and 1995?"; where the five answers are:
1. Yes, as a refugee/displaced person (8.35%);
2. Yes, for a job (0.21%);
3. Yes, to participate in a war (0.13%);
4. Yes, for some other reason (1.68%);
5. No (89.63%).
We identify displaced individuals as ones who reported being a refugee or displaced per- son in war period, while the control group is everyone else.5
Second, CAHS contains data on the county of residence just before the war (on March 31, 1991), which we use to construct an instrument in order to address the potential en- dogeneity of the displacement status. Therefore, we only include individuals who resided in Croatia in pre-war 1991, excluding individuals that lived in other parts of former Yu- goslavia or some other country in 1991. This also implies that the large influx of individ- uals who came to Croatia fleeing from the war in Bosnia and Herzegovina is not a part of the analysis.
Third, CAHS was collected in 2003, which coincides with the return of the majority of internally displaced individuals to their homes. In particular, out of 220,000 internally
5A disproportionately small number of veterans who reported war participation as migration (500 thou- sand individuals has veteran status) can be explained by two reasons. The first one is the local place of war service, so individuals who served did not change residence, while the second is the fact that participating in the war was not perceived and reported as migration.
18 displaced Croatians during the war, in April 2003 around 16,000 individuals remained displaced (Global IDP Database, 2004), which is similar to the return pattern of displaced individuals in CAHS as in 2003 88.5% of the displaced individuals had the same county of residence as in 1991. Therefore, CAHS captures health dimensions of displaced indi- viduals shortly after they have returned to their homes. Note that CAHS does not include individuals that stayed displaced outside Croatia until 2003.6 As we include only individ- uals who were living in Croatia in pre-war 1991 and at the time of the survey collection in 2003, thus excluding a large influx of refugees from Bosnia during the 1992-1995 war in Bosnia, as well as the Serbian minority in Croatia that migrated when Croatia reclaimed its occupied territories in 1995, we speculate that we have run our analysis mostly on ethnic Croats (ethnicity is not recorded in the data set). While this may induce sample- selection concerns, we argue that the ethnic key on which the return of displaced has unfolded supports the view that sample-selection is random with respect to health. In par- ticular, prior to the war, in ethnically mixed areas, both ethnicities shared the language, culture and lifestyle.
We restrict our analysis to females, due to the following reasons. First, CAHS does not provide information on the war-veteran status. Therefore, if an individual reported not being displaced and served in the war, (s)he would be included in the control group (non- displaced). As most of the individuals who served in the war are males, we exclude males to avoid including war veterans in the control group. Second, given male war mortality there might be non-random sampling of males into the survey.
CAHS is successful in recording post-displacement outcomes, also it provides limited, yet useful, information prior to displacement (the county of residence), but fails to provide any information during the displacement. In particular, we do not observe the duration of displacement, locus of displacement (whether a person was a refugee or an internally displaced person) nor the type of accommodation during the exile, all of which is relevant
6This includes ethnic Croats, as well as Serbs. In fact the Serbian population in Croatia decreased from 581 thousand in 1991 to 201 thousand in 2001 (Census of Population, 1991, 2001).
19 in explaining the severity of the displacement effect (Porter and Haslam, 2001).
To construct the instrument for the displacement status we utilize information on pre-war county of residence to construct the approximation for war intensities across counties. As an instrument we use the portion of civilian casualties in county population obtained from Živic´(2001). 7 Figure1 shows the number of civilian casualties across counties per 1,000 inhabitants, which is the instrument we use.
To sum up, the treatment group is composed of displaced females, older than 25 at the beginning of the war, most likely ethnic Croats, who recently returned to their pre-war residence; while the control group is composed of their non-displaced counterparts. Table 7 presents the descriptive statistics of outcome variables for females across the displace- ment status.
Table 1 — Descriptive statistics of health outcomes
Displaced (N = 392) Non-displaced (N = 4,304) Difference Mean Std. dev. Mean Std. dev. Measured outcomes No hypertension 0.444 0.497 0.483 0.500 –0.039 No tachycardia 0.673 0.470 0.734 0.442 –0.060 No obesity 0.753 0.432 0.732 0.443 0.021 Self-assessed outcomes Healthy 0.355 0.479 0.422 0.494 –0.068∗∗ SF-36 physical –0.160 1.043 0.015 0.995 –0.175∗∗ SF-36 emotional –0.223 1.031 0.020 0.995 –0.243∗∗∗
Note: Column "Difference" represents a difference in mean of a given outcome between non-displaced and displaced individual. Details on outcomes can be found in the section below. ∗p<0.1; ∗∗p<0.05; ∗∗∗p<0.01
7Includes killed, exhumed, missing and civilians killed on freed territories during the presence of United Nations Protective Force and United Nations Confidence Restoration Operation in Croatia.
20 Figure 1 — Civilian casualties by county
Civilian casualties by county (per 000) 15 10 5 0
21 I.4.E mpirical strategy
We estimate the effect of displacement on health with a linear two-stage regression model:
0 0 healthi j = β displacedi j + δ xi + θ w j + i j (1) 0 0 displacedi j = λ civilian j + φ xi + ϕ w j + νi j
where healthi j represents a health outcome of a person i who before the war lived in a county j = 1, ..., 21. In particular, we define six different health outcomes healthi j:
1. No hypertension: 1{systolici j < 140 mm Hg & diastolici j < 90 mm Hg}, i.e. an indicator taking the value one if a person i who lived in a county j has systolic and diastolic blood pressure below 140 and 90 mm Hg, respectively.
2. No tachycardia: 1{pulsei j < 100 bpm}, i.e. an indicator taking the value one if a person i who lived in a county j has pulse below 100 beats per minute.
3. No obesity: 1{bmii j < 30}, i.e. an indicator taking the value one if a person i who lived in a county j has Body Mass Index below 30.
4. Healthy: 1{excellenti j | very_goodi j | goodi j}, i.e. an indicator taking the value one if a person i who lived in a county j has reported of being in excellent, very good or good health.
5. SF-36 physical: subjective measure of physical health derived from Short Form (36) Health Survey questionnaire. Higher value indicates better health; standardized to have mean zero and variance one.
6. SF-36 emotional: subjective measure of emotional health derived from Short Form (36) Health Survey questionnaire. Higher value indicates better health; standard- ized to have mean zero and variance one.8
8More on SF-36 scoring can be found at http://www.rand.org/health/surveys_tools/mos/ 36-item-short-form/scoring.html.
22 The variable displacedi j takes the value one if a person i who before the war lived in a county j was displaced due to war in the 1991-1995 period. In particular, displacedi j takes value one if a person answered the question "Did you change your place of living between 1991 and 1995?" with "Yes, as a refugee/displaced person". xi denotes individual level controls such as age group dummies, education dummies and pre-war region of residence, while w j represents controls on pre-war county level: county GDP per capita and unemployment rate in 1990, county portion of Croatian and Serbian population in 1990 as well as portion of young population (below 20) and old popula- tion (above 60).9 Although a richer set of covariates is available—for example, post- displacement labor market outcomes—we avoid using covariates that could be affected by the displacement status. For example, Sarvimäki et al.(2009), Kondylis(2010) and Bauer et al.(2013) show that displacement is significant in explaining income and la- bor market outcomes in Finland, Bosnia and Herzegovina and Germany. Therefore using post-displacement income and labor market variables as controls would qualify as using bad controls (Angrist and Pischke, 2008). As education is affected by displacement (Eder, 2014), we circumvent this problem by excluding individuals that were younger than 25 at the beginning of the war in 1991. We do not include the present county of residence into estimation as 88.5% of displaced individuals has the same county of residence as before the war.
The variable civilian j, which serves as an instrument for the displacement status, repre- sents civilian casualties during the 1991-1995 war in the individual’s i pre-war county of residence. The variable has 21 distinct values and is, in order to facilitate interpretation and sensitivity analysis, standardized to have mean zero and variance one.
We estimate (1) with 2SLS as OLS estimation of health outcomes on the displacement status might produce biased estimates of the coefficient of interest β. As Czaika and Kis-Katos(2009) and Ibáñez and Vélez(2008) show, even when facing conflict and war
9As pre-war region of residence we use 2007-2012 versions of NUTS2 classification which divides Croatia in three regions: Northwestern, Central and Eastern and Adriatic.
23 violence, economic conditions play an important role in displacement decisions. Self preservation is a dominant motive, but other motives are not completely suspended. Fol- lowing Ruiz and Vargas-Silva(2013), an individual i will choose displacement if her utility when going into displacement (D) is higher than the utility of staying (S ), i.e. if
UiD > UiS . Note that UiD = f (RiD, YiD, CiD, OiD, ViD), where RiD is the exposure to war violence, YiD are economic opportunities, CiD are costs of moving, OiD are other relevant factors and ViD are unobserved characteristics. Therefore, an individual might self-select into displacement based on latent health and other health related variables thus making the displacement an endogenous covariate and estimates biased.
Endogeneity concerns are amplified by observed war migration. First, there is no whole population flight from war-inflicted ares. For example, even in the most war-affected re- gions, the east part of Croatia (see Figure 1), we do not observe the displacement of the whole population. In particular, in March 1993, 25.6% of Vukovar-Syrmia county pop- ulation was displaced. The reasons might be within county disparities of war intensity (not all of the county was occupied) or county ethnic mix (mainly ethnic Croats were dis- placed), but selection into displacement cannot be a priori discarded. Second, in CAHS there are individuals who reported being displaced even if they resided in the north-west part of Croatia, which was not inflicted by war. Hence, we observe migration that was war-related but not forced, i.e. there are individuals which were not directly exposed to violence, but mere proximity to conflict triggered the displacement decision.
Given that we observe only few pre-war characteristics (education and age) we cannot use any of the selection-on-the-observables methods, therefore, in order to circumvent the endogeneity of the displacement status, we use an instrumental variable approach, as in Kondylis(2010).
24 I.4.1 Identification
In order to identify the local average treatment effect (LATE) we need to discuss four assumptions: relevance and the exogeneity of the instrument, exclusion restriction and monotonicity (Angrist and Pischke, 2008).
First stage results presented in the first and second column of Table2 show that, although the instrument is based on 21 counties of pre-war residence, it is highly significant in explaining the displacement decision. In particular, an increase of one standard deviation of killed civilians in a county of residence leads to an increase of the probability of being displaced for 8.5 and 5.9 percentage points in the unconditional and conditional model, respectively. The F statistic on the excluded instrument is 20.94 and 29.37 (without and with covariates) so following Stock et al.(2002) we conclude that the correlation between civilian casualties per county and the displacement status for females is strong enough to exclude weak instrument issues. Third column in Table2 presents results on the dis- placement decision without the instrument—while other covariates we use do explain the displacement decision, including the instrument increases the total variation explained by the model. The fourth column of the Table2 presents the falsification test, i.e. we estimate the same model but on migration that occurred due to other reasons.10 Given that civil- ian causalities are not significant in explaining other types of migration implies that our instrument is not picking random variation which reinforces our identification strategy.
To argue the exogeneity of the instrument we need to support the claim that civilian ca- sualties i.e., war intensity, are conditionally random across counties. Although we cannot directly test whether patterns of the conflict in Croatia are driven by pre-war health status in counties, inclusion of pre-war county GDP per capita, pre-war county unemployment rates, region dummies as well as pre-war county demographic structure (percentage of Serbian and Croatian population, percentage of young and old population) in 2SLS es-
10This migration is defined if a person answered "Did you change your place of living between 1991 and 1995?" with "Yes, for some other reason".
25 Table 2 — First stage and falsification
Displaced Other migration
(1) (2) (3) (4) Killed civilians 0.085∗∗∗ 0.059∗∗∗ −0.001 (0.019) (0.011) (0.002) Education Elementary −0.021 −0.019 0.012∗∗∗ (0.016) (0.017) (0.005) High school −0.010 −0.010 0.021∗∗ (0.023) (0.023) (0.009) College 0.006 0.005 0.018 (0.027) (0.027) (0.013) University −0.036 −0.039∗ 0.009 (0.023) (0.023) (0.007) Missing −0.120∗∗∗ −0.112∗∗∗ −0.012∗∗∗ (0.040) (0.039) (0.004) Age Age 31 – 35 0.018 0.017 −0.010 (0.012) (0.013) (0.010) Age 36 – 40 −0.003 −0.006 −0.022∗∗ (0.015) (0.015) (0.011) Age 41 – 45 −0.001 −0.006 −0.024∗∗ (0.014) (0.015) (0.010) Age 46 – 50 −0.021∗∗ −0.023∗∗ −0.026∗∗ (0.011) (0.011) (0.010) Age 51 – 35 −0.026 −0.026 −0.015 (0.016) (0.017) (0.015) Age 56 – 60 −0.025 −0.028∗ −0.012 (0.015) (0.016) (0.015) Age 61 – 65 0.0004 −0.001 −0.017 (0.020) (0.021) (0.014) Age 66 – 70 0.016 0.013 −0.009 (0.023) (0.023) (0.019) Age 71 + 0.019 0.014 −0.009 (0.031) (0.032) (0.019) Pre-war region of residence Central and Eastern 0.108∗∗ 0.108∗ 0.001 (0.054) (0.061) (0.014) Adriatic 0.043 −0.004 −0.013 (0.044) (0.053) (0.013) Constant 0.083∗∗∗ 0.205 0.091 −0.315 (0.018) (0.834) (1.062) (0.440) Pre-war county controls No Yes Yes Yes Observations 4,696 4,696 4,696 4,696 Adjusted R2 0.095 0.141 0.113 0.007 Note: Standard errors are clustered at the pre-war county of residence. Pre-war county controls include county GDP, unemployment rate, percentage of Serbian and Croatian population, percentage of population below 20 and above 60 years of age, all in pre-war 1990. ∗p<0.1; ∗∗p<0.05; ∗∗∗p<0.01
26 timation supports the conditional exogeneity of the instrument. In order to reinforce the claim that civilian casualties are orthogonal to pre-war health or health related variables, note that the war in Croatia started, and was the most intense, in areas where the ethnic structure was mixed. In particular, war was fought most intensely in the area of the Re- public of Srpska Krajina, which was proclaimed by rebel Serbian forces. Therefore as the local variation of war intensity is determined by ethnic structure, our instrument is as good as random with respect to pre-war health status and health related variables.
We devote our whole sensitivity analysis to address possible violations of the exclusion restriction. In fact, it seems plausible that the instrument, civilian casualties across coun- ties, affects health directly, and not only through displacement, thus producing biased estimates. In the sensitivity analysis section we present the results addressing this issue, using the method from Conley et al.(2012).
Monotonicity is satisfied if all individuals that changed the displacement decision due to war, changed it in the same direction, i.e., if there are no defiers. Intuitively, this implies no individuals should have decided to stay in the county of residence due to the war. Violation of monotonicity leads to biased estimates as IV does not necessarily estimate a weighted average of the underlying individual casual effect (Angrist and Pischke, 2008). Although self-preservation reasoning suggests that individuals would run away from war, monotonicity could be violated. In particular, there might be ethnic Serbs in Croatia that decided to stay in their county of residence just because Republic of Srpska Krajina was proclaimed, which induces a bias in the IV estimates Klein(2010). However, as in 1995, when occupied Croatian territory was reclaimed, a number of ethnic Serbs was displaced from Croatia, and as we are including only individuals that resided in Croatia in 1991 as well as in 2003, it seems unlikely that defiers are included in the analysis. Even if there are some defiers, as ? shows, if a subgroup of compliers accounts for the same percentage of population as defiers, 2SLS procedure estimates LATE for the remaining part of compliers. Intuitively, this weaker condition seems likely to hold in present setting as we expect more people fleeing from the war than staying in war-inflicted areas just
27 because of the war.
I.5.R esults
As pointed out by Sarvimäki et al.(2009) and Bauer et al.(2013), we cannot claim that the estimated effects are mean differences between health outcomes of displaced individ- uals and the outcomes in a counterfactual situation where displacement did not occur. Instead, due to the general equilibrium effects of war, we define the counterfactual states as (i) being displaced in war-inflicted Croatia and (ii) not being displaced in war-inflicted Croatia.
Results presented in Table3 reveal several insights on the e ffect of displacement on health outcomes. First, there is compelling evidence that displacement has an adverse effect on measured and self-assessed health outcomes. Displacement significantly increases the risk of hypertension and tachycardia and it also reduces self-assessed health and subjective SF-36 indicators. Incidence of obesity is not affected by displacement status.
Second, these effects are substantial in the magnitude, even to a fault. For example, column (2) in IV estimates indicates that displacement increases probability of suffering hypertension for 75.4 percentage points (90% confidence interval is from 60.1 to 90.7 percentage points), it increases the probability of suffering tachycardia for 40.3 percentage points (90% confidence interval is from 3.5 to 77.1 percentage points), decreases self- assessing health as good for 60.9 percentage points (90% confidence interval is from 33.8 to 88.1 percentage points). Likewise, displacement decreases SF-36 physical health for 0.676 standard deviations (90% confidence interval is from 0.349 to 1 standard deviations) and SF-36 emotional health for 0.812 standard deviations (90% confidence interval is from 0.641 to 0.983 standard deviations). The magnitude of these effects, especially compared to OLS estimates, casts a shadow on the IV estimation validity. We argue that a plausible violation of the exclusion restriction—civilian casualties which approximate the war intensity clearly affect health directly and not only through displacement—actually
28 biases the results towards a more adverse effect of displacement. We devote the next section to address this plausible identification threat.
Third, comparing the significance and magnitude of effects between estimators yields a conclusion that once we account for selection into displacement the adverse effect tends to increase. This implies that there was, in terms of latent health, a positive selection into displacement. Faced with armed conflict, individuals with better latent health, con- ditional on age and education level, were more prone to move. This positive selection into displacement pattern is present also in Kondylis(2010) who finds that more "able" individuals, in terms of labor market, were more likely to be displaced.
Table 3 — War displacement effects
OLS estimates IV estimates Variable mean (1) (2) (1) (2) Measured outcomes No hypertension 0.480 −0.039 0.008 −0.457∗∗∗ −0.754∗∗∗ (0.049) (0.043) (0.048) (0.093) No tachycardia 0.729 −0.060 −0.037 −0.268∗∗∗ −0.403∗ (0.056) (0.053) (0.045) (0.224) No obesity 0.734 0.021 0.041∗ −0.087 0.050 (0.025) (0.024) (0.065) (0.095) Self-assessed outcomes Healthy 0.417 −0.068∗∗ −0.054∗∗ −0.371∗∗∗ −0.609∗∗∗ (0.028) (0.023) (0.106) (0.165) SF-36 physical 0.000 −0.175∗∗ −0.125 −0.664∗∗∗ −0.676∗∗∗ (0.086) (0.077) (0.175) (0.199) SF-36 emotional 0.000 −0.243∗∗∗ −0.190∗∗∗ −0.741∗∗∗ −0.812∗∗∗ (0.072) (0.063) (0.132) (0.104) F on excluded instrument — — — 20.938 29.368 Observations — 4,696 4,696 4,696 4,696
Note: Standard errors are clustered at the pre-war county of residence. Each coefficient is the effect of displacement on a different outcome variable. Model (1) is without covariates, while model (2) includes age- group and education controls, pre-war county of residence, pre-war county unemployment rate and GDP per capita as well as pre-war percentage of Serbian and Croatian population and percentage of population below 20 and above 60 years of age. For all the outcomes a negative coefficient represents an adverse effect. ∗p<0.1; ∗∗p<0.05; ∗∗∗p<0.01
In order to reinforce these findings we also provide results using additional estimates. First concern is that we limit the analysis on individuals who reported conflict as the rea-
29 son of their migration. This could induce bias in estimates as ex post rationalization of the migration decision might be influenced by realized outcomes. For example, more "able" individuals might have reported that the reason for migration was to find a job, while less "able" individuals might have reported that it was due to the conflict, which makes reporting a war as a trigger of migration decision an endogenous response. In order to circumvent this issue, we run the same analysis but broadening the definition of forced displacement on all movers. Results are very similar, both in magnitude and significance. Similarly, we re-run the estimations with different definition of control group, excluding the people who reported migration for other reasons, and results turn out almost identical. Given the potential sorting of displaced individuals into particular counties, we also esti- mate the models using only sample of individuals who have the same county of residence as prior to the war, and again, the results are similar both in magnitude and significance.
11
Next, we check the robustness of the results by excluding the most war-affected county (Vukovar-Syrmia county). As can be seen from Figure1, Vukovar-Syrmia County (east- ernmost county) is a clear outlier in terms of civilian casualties. After excluding this county, we are left with 4,487 observations (313 displaced and 4,174 controls). Results, shown in Table6, show that displacement has an adverse and significant e ffect on SF-36 physical and emotional health.
We also check we only include counties that were more severely hit by the war. In par- ticular, we exclude counties that had lees than 0.05% civilian casualties, so we include 12 counties with, in total, 1,858 observations (359 displaced and 1,499 controls). Results reinforce the conclusions of the baseline specification.12
As already noted, implausibly large magnitude of the effects might come from a violation of the exclusion restriction, which we address in detail in the following section.
11Results are not presented due to brevity. 12Results of all robustness checks are not presented due to brevity.
30 I.5.1 Sensitivity analysis
In this section, we relax the exclusion restriction assumption needed for the identification of IV. The instrument, portion of civilian casualties per county, is reflecting war intensity across counties and there is substantial evidence that exposure to war directly affects long run health dimensions, for example Kesternich et al.(2014) and Akbulut-Yuksel(2014). During the war in Croatia more than 37,000 people were injured (Perkovic´ and Puljiz, 2001), which produces a long-term impact on health. Therefore it might be restrictive to claim that the instrument affects the health exclusively through displacement, especially given that the data set does not record disabilities. In order to address this potential viola- tion of the exclusion restriction we use a method from Conley et al.(2012). Suppose we have one endogenous regressor x, and one instrument z:13
y = βx + γz + (2) x = λz + ν
p If γ = 0, the exclusion restriction holds, but if γ , 0, then βˆIV → β + γ/λ. As the instrument might affect the health dimension in the same direction as the displacement, IV estimates are biased towards a more adverse effect of displacement. To account for the possibility of γ , 0 (in particular, for γ < 0) we apply union of confidence interval method from Conley et al.(2012).
In the union of confidence intervals we need to specify the support of γ, G. If the true
γ is γ0 ∈ G, we can run IV estimation on (y − γ0z) = βx + . After obtaining βˆ(γ0) we construct (1 − α) confidence interval for this particular estimate. Repeating this procedure for different γ ∈ G and taking the union of confidence intervals gives us (1−α) confidence interval for the parameter of interest under the violation of the exclusion restriction:
13It is straightforward to accommodate the model for covariates, see the Appendix of the 2007 working paper version of Conley et al.(2012).
31 [ CIN(1 − α) = CIN(1 − α, γ0) (3)
γ0∈ G
For each of the health outcome we restrict γ ∈ [−0.05, 0], where the upper bound is 0 as we discard the possibility that exposure to war affects health in a positive way. In order to provide some insight regarding lower bound of the support of γ, we use a reduced-form estimate for a given health outcome. Note that the γ for which the IV point estimate is zero is actually a reduced-form estimate. Intuitively, if the entire reduced-form estimate is coming from the direct effect of instrument on an outcome—violation of exclusion re- striction, i.e. γ—endogenous regressor (treatement) is not affecting the outcome. There- fore, benchmarking the magnitude of violation of exclusion restriction with reduced-form estimate provides insight how sensitive results to violation of exclusion restriction are.
Figure4 presents the results of the sensitivity analysis. X-axis represents γ i.e. degree of violation of the exclusion restriction, Y-axis presents the effect of displacement on a given health outcome, gray area represents the 90% confidence interval given the γ, while the solid black line presents the point estimate; to facilitate interpretation we also add a zero line (red line). Note that the γ for which the point estimate equals zero is actually a reduced-form estimate.
X-axis displays how strong does the violation of the exclusion restriction need to be in order for displacement to turn insignificant (upper bound of 90% confidence intervals hits zero). For example, in the case of variable No hypertension, the effect of displacement turns out to be insignificant when the effect of the instrument is -0.038. This translates to the following interpretation: displacement is insignificant in explaining hypertension if a one standard deviation increase of killed civilians increases hypertension incidence for 3.8 percentage points or more. As the reduced-form estimate for No hypertension is -0.045 we conclude that even with severe departures from exclusion restrictions the displacement still has significant and adverse effect on hypertension.
32 Table4 gives the same results in a more compact way. Column (1) displays reduced form estimates, column (2) shows how strong does the violation of exclusion restriction need to be in order for the displacement effect to turn insignificant, while column (3) shows point estimate of the displacement effect for a γ for which the effect turns insignificant.
Results provide compelling evidence that hypertension, self-assessed health as well as both SF-36 measures—even with severe departures from the exclusion restriction—are still adversely affected by displacement. As already mentioned, displacement is insignif- icant in explaining hypertension if a one standard deviation increase of killed civilians increases hypertension incidence for 3.8 percentage points or more, which is more than 84% of the magnitude of the reduced form effect. The same is true for self-assessed health and both SF-36 measures, where the γ needs to be 61%, 45% and 66% of the reduced- form estimate, respectively, in order for the effect turn insignificant. Also, looking at the third column of Table4, we see that, once we allow for the instrument to a ffect outcomes directly, the magnitude of the effect of displacement is not so implausible. However, it is hard to determine whether these effects are practically important after allowing for a violation of exclusion restriction.
33 Figure 2 — Violation of exclusion restriction
(a) No hypertension (b) No tachycardia
0.3
0.5 0.0
-0.3 0.0
-0.6 Effect ofdisplacement Effect ofdisplacement -0.5
-0.9
-0.05 -0.04 -0.03 -0.02 -0.01 0.00 -0.05 -0.04 -0.03 -0.02 -0.01 0.00 g g
(c) No obesity (d) Healthy
0.5
0.8
0.0
0.4
-0.5 Effect ofdisplacement Effect ofdisplacement
0.0
-0.05 -0.04 -0.03 -0.02 -0.01 0.00 -0.05 -0.04 -0.03 -0.02 -0.01 0.00 g g
(e) SF-36 physical (f) SF-36 emotional
0.5
0.0
0.0
-0.5 -0.5 Effect ofdisplacement Effect ofdisplacement
-1.0 -1.0 -0.05 -0.04 -0.03 -0.02 -0.01 0.00 -0.05 -0.04 -0.03 -0.02 -0.01 0.00 g g
Note: Figure presents the effects of displacement allowing for the violation of the exclusion restriction using the Union of confidence interval, where γ represents the violation of the exclusion restriction in Equation (2). On both panels the black line presents the point estimate, while the gray surface presents the 90% confidence interval of the displacement effect under different degrees of violation of the exclusion restriction.
34 Table 4 — Sensitivity analysis
γ for which the effect Point estimate when the Reduced form estimates turns insignificant effect turns insignificant (1) (2) (3) Measured outcomes No hypertension –0.045∗∗∗ –0.038 –0.124 (0.005) No tachycardia –0.024∗ –0.002 –0.363 (0.012) No obesity 0.003 0 –0.050 (0.006) Self-assessed outcomes Healthy –0.036∗∗∗ –0.022 –0.241 (0.009) SF-36 physical –0.040∗∗ –0.018 –0.369 (0.016) SF-36 emotional –0.048∗∗∗ –0.032 –0.267 (0.012)
Note: Standard errors are clustered at the pre-war county of residence. Reduced form estimates includes all the controls as the column (2) in the IV specification in Table3. Second column shows γ for which the effect of displacement turns insignificant, while the third column shows point estimate for a such γ. ∗p<0.1; ∗∗p<0.05; ∗∗∗p<0.01
I.6.C onclusions
This paper provides an analysis of health consequences of war-related forced displace- ment that occurred in Croatia during 1991-1995 which accompanied the demise of Yu- goslavia. During the course of the war in Croatia more than half a million of individuals of all ethnicities were displaced, more than 10% of Croatia’s pre-war population. In or- der to analyze the health effects of displacement, we use Croatian Adult Health Survey (CAHS) collected in 2003, when most of the internally displaced individuals returned to their homes. We take a stand that displacement, although to an extent a forced action, is a form of migration, and thus endogenous. In order to avoid the bias in estimates due to the self-selection into displacement, we adopt an instrumental variable approach. In particular, using a retrospective question on pre-war county of residence, we use civilian casualties per county as an instrument for displacement.
35 Results indicate that various health dimensions are adversely affected by displacement as 90% interval estimates exclude that there is no effect on the incidence of hypertension, self-assessed health, and both emotional and physical Short Form Health Survey (SF-36) dimensions. In addition, we found that IV estimates are quantitatively higher than OLS estimates which indicates positive selection into displacement. These baseline results are supported by numerous robustness checks.
In order to address a likely violation of the exclusion restriction, we also apply a method from Conley et al.(2012), that enable us to perform inference on the e ffect of displace- ment even if the instrument is directly affecting health outcomes. Results from the union of confidence interval indicate that even with sev ere departures from the exclusion restric- tion we still find significant adverse effects of displacement. In particular, the violation of exclusion restriction must be more than a half of the reduced-form effect in order for the effect of displacement to turn insignificant. While this indicates that our findings are robust, is hard to determine whether these effects are practically important after allowing for substantial violation of exclusion restriction. This research, enhancing the identifi- cation of causal effect of displacement, contributes to the growing literature of conflict consequences, which, unfortunately, will only be growing.
36 I.7.A ppendix
Table 5 — Summary statistics
Mean Std. dev. Min Max Measured outcomes No hypertension 0.480 0.500 0 1 No tachycardia 0.729 0.445 0 1 No obesity 0.734 0.442 0 1 Self-assessed outcomes Healthy 0.417 0.493 0 1 SF physical 0.000 1.000 -2.148 1.599 SF emotional 0.000 1.000 -2.465 1.592 Age Age 26 – 30 0.093 0.290 0 1 Age 31 – 35 0.111 0.315 0 1 Age 36 – 40 0.112 0.315 0 1 Age 41 – 45 0.120 0.325 0 1 Age 46 – 70 0.104 0.305 0 1 Age 51 – 55 0.121 0.326 0 1 Age 56 – 60 0.127 0.333 0 1 Age 61 – 65 0.109 0.312 0 1 Age 66 – 70 0.069 0.253 0 1 Age 71 + 0.033 0.180 0 1 Education No education 0.265 0.441 0 1 Elementary 0.283 0.451 0 1 High school 0.332 0.471 0 1 College 0.055 0.228 0 1 University 0.059 0.236 0 1 Missing 0.006 0.077 0 1 Pre-war region of residence Northwestern 0.394 0.489 0 1 Central and Eastern 0.297 0.457 0 1 Adriatic 0.309 0.462 0 1
37 Table 6 — War displacement effects excluding Vukovar-Syrmia County
OLS estimates IV estimates Variable mean (1) (2) (1) (2) Measured outcomes No hypertension 0.486 −0.035 0.019 −0.453∗∗∗ −0.233 (0.059) (0.049) (0.144) (0.219) No tachycardia 0.733 −0.025 0.002 −0.232 −0.094 (0.055) (0.046) (0.171) (0.277) No obesity 0.735 0.014 0.034 −0.047 0.336∗∗ (0.029) (0.026) (0.140) (0.157) Self-assessed outcomes Healthy 0.423 −0.053∗ −0.046∗ −0.113 −0.068 (0.028) (0.026) (0.143) (0.202) SF-36 physical 0.010 −0.173∗ −0.130 −0.526∗ −0.659∗∗ (0.104) (0.093) (0.318) (0.299) SF-36 emotional 0.011 −0.242∗∗∗ −0.190∗∗∗ −0.677∗∗ −0.796∗∗ (0.086) (0.074) (0.302) (0.374) F on excluded instrument — — — 233.209 109.311 Observations — 4,487 4,487 4,487 4,487
Note: Standard errors are clustered at the pre-war county of residence. Each coefficient is the effect of displacement on a different outcome variable. Model (1) is without covariates, while model (2) includes age- group and education controls, pre-war county of residence, pre-war county unemployment rate and GDP per capita as well as pre-war percentage of Serbian and Croatian population and percentage of population below 20 and above 60 years of age. For all the outcomes a negative coefficient represents an adverse effect. ∗p<0.1; ∗∗p<0.05; ∗∗∗p<0.01
38 II.G eneral versus Vocational Education:Lessons from a
Quasi-experiment in Croatia
II.1.I ntroduction
The debate on general versus vocational education has been an important part of policy makers’ and academics’ agenda. As both educational systems have their benefits, there exists a well-known general-vocational trade-off. In particular, skills acquired by voca- tional training may ease the transition into the labor market, but may become obsolete at a faster rate; while general education gives access to broader knowledge that can serve as a sound basis for subsequent learning and specialization (Hanushek et al., 2017). Verhaest and Baert(2015) characterize general versus vocational schooling as a trade-o ff between lower risk of bad match persistence later on, and higher employment chance and better match at the start of the career.
Some authors claim that general education is especially important for the fast-changing economy, as individuals can change occupations and adapt new technologies more quickly (Goldin, 2001; Hanushek et al., 2017). Adopting this view suggests that a more general education should pay a labor market premium in transition and post-transition countries. With the fall of socialism and the establishment of market-oriented economies in the 1990s, countries of the Eastern Bloc went through profound institutional and political changes. The economy was affected drastically as business activities turned to different sectors and technologies which translated into different sets of skills required on the labor market. Was a more general education beneficial for individuals in this changing age?
Answering these questions is not an easy task as educational choice suffers from self- selection—comparing labor market outcomes of individuals with general and vocational education would reflect unobserved differences across individuals making the estimates biased (Ryan, 2001).
39 To shed some light on this matter, in this paper we identify the causal effect of a com- prehensive high-school reform implemented in Croatia in 1975/76 and 1977/78. Prior to the reform, after completion of eight-year compulsory elementary school pupils, based on their grades and interests, could enroll academic (gymnasium), technical or vocational high school. The reform split high-school education into two phases—the first phase, two years of general curriculum common to all students regardless of the school enrolled, and a second phase, which prepared students for a particular profession. This introduced three novelties. Firstly, an extra educational decision as to where to continue the sec- ond phase was introduced; therefore, the separation into vocational tracks was postponed, i.e. tracking was reduced. Secondly, individuals could not enter a vocational school di- rectly after an eight-year compulsory elementary school—instead, they needed to attend two additional years of general education. Lastly, all programs, including once academic and general, were given vocational and paraprofessional context. Exploiting elementary school age entry rules and the timing of the implementation of the reform we are able to use regression discontinuity design on pooled Labor Force Surveys 2000–2012.
We test whether reduced tracking affected the highest educational attainment, years of schooling and the field of study. We also analyze if two extra years of general curriculum affected labor market prospects of nongymnasium high-school graduates (technical and vocational high-school graduates) in terms of wages, years of employment, probability of being unemployed as well as the probability of being inactive.
Results indicate that the reform, on average, reduced the probability of having university education. The estimated negative effect is varying from 2.7 to 5.5 percentage points. We argue that this effect came from attaching paraprofessional and vocational context to once general programs. In the old system, gymnasiums were perceived as a preparation for university education, while in the reformed system, gymnasiums de facto existed, but they were associated with some vocation, making graduates of general programs employable. This interpretation is supported by the drop in university enrollment rates.
40 We also observe different effects across gender. For male pupils we find that the proba- bility of completing only elementary school increased, which indicates a high incidence of first-phase dropouts. The first phase was mostly general curriculum, which might have been a challenge for low-ability pupils who would otherwise be able to complete a three- year vocational school. As in the whole sample, we also observe a drop in the probability of having a university education for males.
On the other hand, we do not find any adverse effects for females. The only significant effect is an increase in the probability of attending some university education. We argue that this heterogeneity in the reform effects is driven by different selection into school- ing across genders. While most of the males could go to school, a significantly lower portion of females enrolled secondary schooling, due to informal barriers, such as gender and family roles. We argue that these informal barriers selected more-able females into schooling who had no problems completing the first phase, and were actually motivated to continue education after high school. We also observe that a portion of females shifted from teacher education and services into social sciences.
Restricting our sample on nongymnasium high-school graduates, we find that the two additional years of general education did not positively affect individuals’ labor market prospects. This lack of premium on more general education is surprising, given the po- tential upward bias of the estimates. In particular, as the reform caused a drop in the probability of completing a university, the nongymnasium high school sample contains different ability distributions before and after the reform. We conclude that the observed general vocational wage differential is mainly driven by self-selection into the type of high school.
Although these results are specific for the socialist Yugoslavia, we believe they carry some external validity. Croatia, at that time a part of former Yugoslavia, had an economic sys- tem called “self-managment” where socially owned companies were profit maximizing— labor actually employed capital. This hybrid system had some characteristics of market
41 economies. For example, in the 1960s interregional transfers were reduced and enterprise taxes were lowered in order to further push enterprises towards the market, and banks were established as financial intermediaries (Milenkovitch, 1977). Also, workers received wages in two parts: a fixed wage, based on job evaluation and labor market criteria, and a variable part based on the level of net profits of the enterprise (Wachtel, 1972), which gave profit- and utility-maximizing incentives to firms and individuals.
This paper contributes to the empirical literature on the nexus between additional years of general education and labor market outcomes. For example, Hanushek et al.(2017), using difference-in-differences approach and pooling individuals from 11 countries, pro- vide results that support the general-vocational education trade-off as they find that indi- viduals with general education do initially have worse employment outcomes, but their perspective improves as they get older. On the other hand, research that relies on quasi- experimental evidence contrast these results. Using the educational reform in the 1970s in Romania, Malamud and Pop-Eleches(2010) find that more years of general education did not affect labor market participation and earnings. Oosterbeek and Webbink(2007), ana- lyzing the reform of the Dutch vocational schools, also find no evidence of premium on more general years of schooling. Analyzing a pilot scheme administrated in Sweden that introduced more comprehensive upper secondary education, Hall(2012) finds no e ffect of more general education on university enrollment and earnings, as well as no evidence that attending general education reduces unemployment risk during the 2008–2010 crisis (Hall, 2013).
The rest of the paper is organized as follows: section 2 explains the educational reform in Croatia, section 3 explains the methodology and data, section 4 presents the results, while section 5 the conclusion.
42 II.2.E ducational reform in Croatia
Prior to the reform in the 1970s, education in Yugoslavia, and hence Croatia, was reg- ulated at the federal level by the General Law on Education from 1958. Children en- rolled an eight-year compulsory elementary school, on average, at the age of seven. Upon the completion of elementary school, depending on their performance and aptitude, they could continue in one of the following secondary schools: gymnasium, art school, tech- nical school, trade or vocational school, teacher’s school or military secondary school. Duration of the secondary school depended on the type of the school, ranging from three years for trade or vocational schools for skilled workers to five years for teachers, but averaging around four years. After successfully completing high school and earning a diploma, pupils could enroll into a higher educational institution or enter the labor market (Georgeoff, 1982).
On the tenth Congress of the League of Yugoslav Communists in 1974 the basis for the so-called “directed” education was established. The reform redesigned high-school edu- cation abolishing general secondary schooling (gymnasiums), making all secondary edu- cation vocation-oriented. In words of Stipe Šuvar, then Secretary of State for Education in Croatia, the educational system was flawed as: “Homo faber and homo sapiens are so- cially separated, alienated, opposed in the existence of different classes; and the primary purpose of education is to perpetuate these divisions it has, in fact, been developed as a specific ritual which selects a small proportion of the population for the social elites, and places them on a pedestal which is inaccessible to the vast majority of the popu- lation.” (Bacevic, 2016). Indeed, “Although any elemetary school graduate may enter gymnasium, in reality it is somewhat restricted by the realities of socio-economic life in Yugoslavia. ...we tend to find the children of the social and political elites in the gym- nasium and the children of the general populace in the vocational and technical schools.” (Farmerie, 1972).
Therefore, the objectives of the reform were: (i) a more equal distribution of students from
43 various socio-economic backgrounds enrolled in secondary schools of various types; (ii) a greater emphasis on the development of specific occupational skills with the goal of easier school to work transition; (iii) a promotion of greater equality of access to education and employment opportunities; and (iv) a closer integration of the schooling system with the needs of the social system and self-management (Obradovic´, 1986).
Under the new educational system, the high school was split into two phases, both ad- ministered at the so-called school centers. The first phase, which lasted for two years, was common for all students irrespective of the type of the secondary school they en- rolled. The majority of the first-phase curriculum was general (85% according Obradovic´ (1986)): official language, chemistry, biology, physics, geography, mathematics and his- tory. Selection into the first phase was based on elementary school performance—pupils had to apply and were selected based on the grades form the last two grades of elemen- tary school. Upon the completion of the first phase, students could enter the labor market or continue to the second phase. The second phase was designed to provide vocational preparation. In total, programs for 36 professions and more than 350 occupations were available (UNESCO, 1984), and programs lasted for one or two years. All students who completed the first-phase could apply for any of the second phase programs, but selection was based on the grades from the first phase. All high schools were renamed as school centers associated with some vocation. For example, a mathematical gymnasium was renamed the school center for mathematics and informatics, so programs for general edu- cation were still de facto available but were given a vocational or paraprofessional context. For example, upon completing the school center for mathematics and informatics a person would get a vocation titled “technician for mathematics and natural sciences”.
The first phase of the new high-school system was implemented in all secondary education in Croatia in the school year 1975/76, for the high-school freshmen, while the second phase was implemented for the same cohort in the school year 1977/78 (UNESCO, 1977). Stylized representation of the reform is depicted in Figure3.
44 Figure 3 — Changes in high-school education in Croatia during the 1975/76 and 1977/78 reform
(a) Before the 1975/76 and 1977/78 reform