جنگ های داخلی آن سوی مرزهای خود: سرمایه انسانی و پیامدهای بهداشتی پناهندگان کشور میزبان

In early 1994, Kagera – a region in northwestern Tanzania – was flooded by more than 500,000 refugees fleeing from the genocides of Burundi and Rwanda. I use this population shock and a series of topographic barriers that resulted in variation in refugee intensity to investigate the short- and long-run causal effects of hosting refugees on outcomes of local children. This strategy provides evidence of adverse impacts over one year after the shock: a worsening of children's anthropometrics (0.3 standard deviations), an increase in the incidence of infectious diseases (15–20 percentage points) and an increase in mortality for children under five (7 percentage points). I also find that intra- and inter-cohort variation in childhood exposure to the refugee crisis reduced height in early adulthood by 1.8 cm (1.2%), schooling by 0.2 years (7.1%) and literacy by 7 percentage points (8.6%). Designs using the distance to the border with Rwanda as an alternative identification strategy for refugee intensity support the findings. The estimates are robust across different samples, specifications and estimation methods and provide evidence of a previously undocumented indirect effect of civil wars on the well-being of children and subsequent economic growth in refugee-hosting communities.

The human suffering and adverse economic consequences inflicted by internal unrest and civil conflicts are evident to all. Wars produce large death tolls, disrupt human and physical capital accumulation, damage the environment, weaken institutions, limit political governance, and erode civil liberties. And their horrors uproot entire populations from their lands, mostly non-combatants. Since civil wars typically go on for many years, these exoduses have been common and on the rise in many parts of the world. Numbers compiled by the United Nations High Commission of Refugees (UNHCR), for instance, hint at an over threefold increase in the number of forced migrants in sub-Saharan Africa between mid 1970s and early 2000s.1 Many articles have examined the socioeconomic impacts of wars on refugees. Instead, this paper focuses on other individuals that are also affected by these displacements and often do not receive the same attention: the host communities. Massive population shocks such as those triggered by most civil conflicts in sub-Saharan Africa can influence the well-being of permanent residents in many ways. The risks, on the one hand, include disease outbreaks, food and land scarcity, unsafe drinking water, wage competition, overburdened school and health care facilities, environmental degradation, and increased criminality. In the particular case of young children, the combined effect of these factors can lead to deficiencies in early childhood development. On the other hand, the arrival of refugees can raise the welfare of their hosts and stimulate their local economies through higher demand, the influx of resources from international humanitarian assistance, and more and improved infrastructure. Establishing whether the positive effects outweigh the negative effects is at the end a subject of empirical discussion since many of these mechanisms operate in different directions and the magnitude of their impacts are rarely known. Notwithstanding the large and growing number of refugee crises, the effects of civil conflicts on local inhabitants in developing countries – especially children – that host refugees remain largely unexplored in the empirical literature. A plausible explanation to the difficulty in testing a causal pathway stems from the large number of omitted factors that might produce unconvincing associations between refugees or permanent resident status and post-conflict socioeconomic outcomes; another obvious reason is the lack of rich data to credibly capture exogenous variation in exposure to the population shock. A natural experiment can help overcome these limitations. In this paper I investigate the short- and long-term causal effects of hosting refugees on children's outcomes in rural Tanzania by exploiting the population flows from the genocides in Burundi (1993) and Rwanda (1994) as a natural experiment. On October, 1993, not long after being democratically elected, the Hutu president of Burundi was assassinated and the country entered a period of civil strife. The Hutu community responded to this by killing thousands of Tutsi civilians; the Burundian army (still controlled by Tutsis) extended the cycle of revenge with a mass-killing of Hutu civilians. Even though numbers vary by source, it was reported at the time that between 100,000 and 150,000 people died in the genocide and approximately 800,000 Burundians were forced to flee their homes. The violent ethnic rivalry spread out months later to Rwanda. On April 6, 1994, the airplane carrying Juvénal Habyarimana and Cyprien Ntyamina (presidents of Rwanda and Burundi, respectively) was shot down as it approached Kigali – the capital and largest city of Rwanda – leading to the death of both presidents. In retaliation, extremist militia groups started the extermination of ethnic Tutsis and moderate Hutus. Over the course of three months, between 800,000 and one million were killed (more than one tenth of Rwanda's population) and at least two million people fled into bordering countries. Tanzania welcomed displaced people for decades and was at some point the host to the largest refugee population in Africa. Kagera, a region located in the northwestern corner of the country, was particularly affected by the enormous influx of refugees from the conflicts in Burundi and Rwanda previously described. Approximately 250,000 Burundians fled into Kagoma and Kagera regions during the first wave of immigration between the end of 1993 and the beginning of 1994. Yet, the largest flow began a few weeks later (April 28, 1994), when more than 250,000 Rwandans forming lines of up to 12 km long flooded into Kagera in less than 24 h, the largest and fastest refugee movement in modern history, according to officials from UNHCR. Overall, the Kagera region hosted over 500,000 refugees from the Rwandan genocide. Together with the influx of Burundians, refugees outnumbered local citizens of the two main recipient provinces, which had populations of roughly 320,000 and 250,000 inhabitants at the pre-war time. The empirical investigation of the human capital consequences of this forced migration on the children of the locals is the main focus of this paper. A normal identification concern is the potentially non-random nature of the location of population inflows into host communities. Estimates that do not address this are probably biased away from the true impact if areas relatively poorer and with unobservable disadvantages are systematically more or less flooded by displaced persons. In the particular case of Kagera, qualitative evidence and anecdotal accounting indicate that refugee settlements (formal and self-settled) were largely concentrated in two provinces: Ngara and Karagwe. For identification purposes, this paper exploits a number of operational and geographic features that explain the exogenous nature of this placement and produce extensive spatial and time variation in the number of refugees hosted across provinces in Northwestern Tanzania. First, the magnitude and timing of the events that led to the displacement of Rwandans and Burundians were largely unanticipated. Second, the magnitude of the exodus made it logistically difficult and expensive for the Government of Tanzania (GoT) and aid organizations to direct refugees evenly across regions within Kagera. Third, and again due to the scale of the problem, 11 out of the 12 largest camps were located in Ngara and Karagwe (relatively closer to the borders with Rwanda and Burundi) to facilitate the future repatriation of refugees. Finally, the identification strategy benefits from the fact that Ngara and Karagwe are adjacent to a chain of mountains, swamps, lakes, and large forest and game reserves that create a band of unoccupied areas. These natural topographic barriers separate these districts from other provinces of Kagera, further limiting the spatial spread of formal and informal refugee settlements to other provinces — and are uncorrelated with the likely determinants of the outcomes of analysis. Furthermore, Tanzania is home to Lake Victoria, the largest lake in Africa with a width of about 240 km. Since Kagera is situated on the southwest shore of the lake, two largely rural regions (Mara and Mwanza) bordering the southeastern shoreline of the lake provide additional natural comparison groups that are thought to be immune to the arrival of refugees. In addition to research designs that employ binary variables to identify these sources of variation, I also make use of geo-referenced data to exploit the distance from the village to the border with Rwanda as an alternative instrument for village-level cross-sectional refugee intensity. Although the well-being of several groups of people may be well affected by large inflows of forced and very poor migrants, this study focuses on the net short- and long-term impacts on local (Tanzanian) children in particular. A double-difference analysis that exploits variation in village-level refugee intensity over time together with pooled cross-sectional and longitudinal household level data are employed to implement the identification strategies noted above. Additionally, for the long-term analysis, I exploit inter-cohort variation in exposure to the onset of the crisis as a control experiment (in a triple-difference framework, D-D-D) based on the lower sensitivity in physical growth (i.e. height) of older cohorts. Reduced-form results offer robust evidence of adverse impacts nearly 1.5 years after the two genocides: a worsening of children's anthropometrics (a shift to the left of the overall distribution of nearly 0.3 standard deviations), an increase of 15 to 20 percentage points in the incidence of infectious diseases and a dramatic increase of approximately 7 percentage points in under-five mortality. Intra- and inter-cohort variation in exposure is also exploited to find that childhood exposure to the massive arrival of refugees reduced height in early adulthood (i.e. ten years after the genocides) by 1.8 cm (1.2%), schooling by 0.2 years (7.1%) and literacy by 7 percentage points (8.6%).2 The robustness of these findings to several and varied confounding factors is also investigated. Overall, the results are not driven by a declining trend in the health status of children in affected areas prior to the two historical episodes, by endogenous migration, attrition and humanitarian assistance, by misspecification biases from the linearity assumption, and by the selection implied by the determinants of survival. The remainder of the paper proceeds as follows. The next section gives background that reviews the previous relevant literature and briefly documents the genocides and the inflows of refugees into northwestern Tanzania. Section 3 describes the datasets used for the empirical analysis. Section 4 presents the identification strategies employed and reports summary statistics, regression results on the short and long-run effects of the population shocks as well as a set of robustness exercises. Section 5 hypothesizes potential mechanisms that could explain the direction and size of the impacts. Finally, Section 6 concludes.

This paper joins previous efforts from an already growing literature that has been examining the contemporaneous and long-run impacts of health shocks suffered in early stages of life on human capital. To date, however, most of the shocks studied have been the result of natural disasters, idiosyncratic events or economic downturns but rarely of large-scale violent conflicts. The evidence of this study (jointly with recently emerging research) contributes to fill this gap by documenting an indirect and long-lasting negative effect of civil wars on the health status and human capital of non-combatant young children in refugee-hosting communities, and very likely on their future economic growth as well. I have presented a set of results that appear to be robust to different subsamples and measures of treatment as well as to alternative specifications, estimation methods and a variety of potentially contaminating issues. However, a major difficulty for papers based on micro-data from small regions lies in the generalization of their results. Despite the peculiar context that shaped the identification strategy followed in this paper (i.e. timing of events, geographic characteristics, location of refugee settlements), the qualitative direction of its findings can probably be extrapolated to refugee movements of similar magnitude in the developing world to shed some light on the possible impacts on the populations that receive them. In the last three decades, Sub-Saharan Africa has registered no less than 15 civil conflicts that have affected nearly three quarters of the countries in the region — not to mention internally displaced persons and the thousands of migrants fleeing political oppression. The socioeconomic characteristics of all these refugees and their hosting communities resemble to a large extent the conditions of vulnerability observed during the refugee crisis in the Kagera region: high levels of poverty, overpopulation, with most people being subsistence farmers and pastoralists that deal with erratic rains and face high levels of disease, malnutrition and death. The empirical findings have implications beyond the short-term. The evidence shows that the negative impacts of childhood exposure at the onset of the refugee migration persisted over time, at least until adolescence, and to some extent are probably irreversible. There is considerable evidence from developing countries consistent with this observation, showing that health shocks and growth lost in early childhood are not only partially offset later in life but correlated with cognitive development deficits, schooling attained, and body size in adulthood (Martorell and Schroeder, 1994). As individuals grow and enter their productive lives, detrimental impacts as the ones documented here can manifest themselves again through negative effects on labor market outcomes and economic productivity.36 These effects can be further exacerbated in rural communities where physical strength and healthiness are key determinants of adult work capacity in labor-intensive livestock and agricultural occupations — by far the most prominent activities in Kagera. Back of the envelope calculations using estimates from other authors give a sense of the magnitude of these costs: the worsening of 0.3 standard deviations in the height for age of children in Northwestern Tanzania could translate into a fall of 2.8% in their earnings in adulthood (based on the point estimates on the earnings-height elasticity for Brazil from Strauss and Thomas, 1997), whereas the reduction of 0.2 years in school attainment found for the affected cohort could account for as much as 7.5% lower wages by adulthood (based on the average returns to primary education in Sub-Saharan Africa summarized by Patrinos and Psacharopoulos, 2002). Finally, from a policy perspective, the results of this paper together with those of previous research offer evidence to promote and mobilize global assistance in the scale required. Unfortunately – but understandably to some extent – some low-income countries overburdened by hosting a large number of displaced people have imposed restrictions on the acceptance of more refugees in the past. Evidence arising from this paper could be argued to justify such actions. Closing the borders, however, is far from the solution. Instead, as the findings seem to suggest, what is needed is a more comprehensive response from international donors and aid agencies – assuming obviously that this assistance in fact works – to prevent that the welfare of civilians could be determined by their proximity to these events.