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Esteban, Joan, Laura Mayoral and Debraj Ray. 2012. "Ethnicity and Conflict: An Empirical Study." American Economic Review, 102(4): 1310-42.



We examine empirically the impact of ethnic divisions on conflict, by using a specification based on Esteban and Ray (2011). That theory links conflict intensity to three indices of ethnic distribution: polarization, fractionalization, and the Gini-Greenberg index. The empirical analysis verifies that these distributional measures are significant correlates of conflict. These effects persist as we introduce country-specific measures of group cohesion and of the importance of public goods, and combine them with the distributional measures exactly as described by the theory. (JEL D63, D74, J15, O15, O17)



Esteban and Ray (2011)の定式化を用いて、紛争に与える民族分断のインパクトを実証的に明らかにする。彼らの理論では、紛争の大きさを3つの民族分布の指数(分極、分断、ジニ・グリーンバーグ指数)に関連付けている。これらの分布指数が紛争と有意な関係であるかどうかをこの実証研究で検証する。集団結束度および公共財の重要性について国別の尺度を導入し、分布指数とそれらの尺度を組み合わせることで、Esteban and Rayの理論が描くような効果を実証している。



最近のトップジャーナルに掲載された紛争研究においては、理論と実証の両方から影響力をもつ研究。前年の2011年にEsteban and Rayが理論をAERに載せ、この二人に計量のMayoralを迎えて実証した豪華二本立て。Rayは言わずと知れた開発経済学の大家だが、彼は2012年にも紛争に関する理論をJPEに載せている(Mitra and Ray 2012)。


Nunn, Nathan. 2008. The long-term effects of Africa's slave trades. Quarterly Journal of Economics 123(1): 139-176.



Can part of Africa's current underdevelopment be explained by its slave trades? To explore this question, I use data from shipping records and historical documents reporting slave ethnicities to construct estimates of the number of slaves exported from each country during Africa's slave trades. I find a robust negative relationship between the number of slaves exported from a country and current economic performance. To better understand if the relationship is causal, I examine the historical evidence on selection into the slave trades and use instrumental variables. Together the evidence suggests that the slave trades had an adverse effect on economic development.





Michalopoulos, S., & Papaioannou, E. (2016). The long-run effects of the scramble for Africa. The American Economic Review, 106(7), 1802-1848.



We explore the consequences of ethnic partitioning, a neglected aspect of the Scramble for Africa, and uncover the following. First, apart from the land mass and water bodies, split and non-split groups are similar across several dimensions. Second, the incidence, severity, and duration of political violence are all higher for partitioned homelands which also experience frequent military interventions from neighboring countries. Third, split groups are often entangled in a vicious circle of government-led discrimination and ethnic wars. Fourth, respondents from survey data identifying with split ethnicities are economically disadvantaged. The evidence highlights the detrimental repercussions of the colonial border design.





Dustmann, C., Schönberg, U., & Stuhler, J. (2016). Labor supply shocks, native wages, and the adjustment of local employment. The Quarterly Journal of Economics, qjw032.



By exploiting a commuting policy that led to a sharp and unexpected inflow of Czech workers to areas along the German-Czech border, we examine the impact of an exogenous immigration-induced labor supply shock on local wages and employment of natives. On average, the supply shock leads to a moderate decline in local native wages and a sharp decline in local native employment. These average effects mask considerable heterogeneity across groups: while younger natives experience larger wage effects, employment responses are particularly pronounced for older natives. This pattern is inconsistent with standard models of immigration but can be accounted for by a model that allows for a larger labor supply elasticity or a higher degree of wage rigidity for older than for young workers. We further show that the employment response is almost entirely driven by diminished inflows of natives into work rather than outflows into other areas or nonemployment, suggesting that “outsiders” shield “insiders” from the increased competition.




Heller, S. B., Shah, A. K., Guryan, J., Ludwig, J., Mullainathan, S., & Pollack, H. A. (2016). Thinking, fast and slow? Some field experiments to reduce crime and dropout in Chicago. The Quarterly Journal of Economics, qjw033.



We present the results of three large-scale randomized controlled trials (RCTs) carried out in Chicago, testing interventions to reduce crime and dropout by changing the decision making of economically disadvantaged youth. We study a program called Becoming a Man (BAM), developed by the nonprofit Youth Guidance, in two RCTs implemented in 2009–2010 and 2013–2015. In the two studies participation in the program reduced total arrests during the intervention period by 28–35%, reduced violent-crime arrests by 45–50%, improved school engagement, and in the first study where we have follow-up data, increased graduation rates by 12–19%. The third RCT tested a program with partially overlapping components carried out in the Cook County Juvenile Temporary Detention Center (JTDC), which reduced readmission rates to the facility by 21%. These large behavioral responses combined with modest program costs imply benefit-cost ratios for these interventions from 5-to-1 up to 30-to-1 or more. Our data on mechanisms are not ideal, but we find no positive evidence that these effects are due to changes in emotional intelligence or social skills, self-control or “grit,” or a generic mentoring effect. We find suggestive support for the hypothesis that the programs work by helping youth slow down and reflect on whether their automatic thoughts and behaviors are well suited to the situation they are in, or whether the situation could be construed differently.


シカゴで実施された3つの大規模RCTによって、経済的に恵まれない青少年の意思決定が変化し、犯罪やドロップアウトが減少したかを検証した結果を提示する。検証したRCTのうち2つは、非営利青少年ガイダンスによって開発されたBecoming a Man(BAM)というプログラムで、2009-2010年および2013-2015年に実施された。この2つのRCTに関する研究結果は、BAMプログラム参加者においては介入期間中の総逮捕者数が28-35%減少し、暴力犯罪者数は45-50%減少、school engagement*1が改善され、また、フォローアップ・データがある一つ目のRCTにおいては卒業率が12-19%上昇した。3つ目のRCTは、クック郡少年臨時拘置所(JTDC)で実施された、部分的に重複した構成のプログラムを検証し、結果として施設への再入場率が21%削減したことが分かった。以上の、甚大な行動的反応と僅かなプログラム費用の組合せの結果より、費用便益は5:1から30:1以上であることが示唆される。メカニズムに関する我々のデータセットは理想的状況ではないが、この分析結果がRCT以外の諸要因(心の知能指数や社会技能、自制心、”グリット”、generic mentoringによる影響)による影響ではないことを明らかにした。この研究から、我々は以下の仮説について示唆的に支持する:このプログラムが、青少年のスロー・ダウンを促し、自分の自動思考や行動が自らの状況に適しているかどうか、また自らの状況を別の視点で捉えることができるかどうかを反映する。


JELコード と ジャーナル略称




  • A:一般
  • B:経済思想史・方法
  • C:数理・計量
  • D:ミクロ
  • E:マクロ・財政
  • F:国際
  • G:金融
  • H:公共
  • I:医療・教育・福祉
  • J:労働・人口
  • K:法と経済学
  • L:産業組織論
  • M:経営・ビジネス
  • N:経済史
  • O:経済発展
  • P:経済システム
  • Q:農業・資源・環境
  • R:都市・地域・不動産
  • Y:その他
  • Z:その他特別



  • AER: American Economic Review
  • QJE: Quarterly Journal of Economics
  • JPE: Journal of Political Economy
  • ETCA: Econometrica
  • REStud: Review of Economic Studies