Re-examining Economic Shocks and Civil Conflict
重新检验了降雨量作为经济增长工具变量对非洲国内冲突的影响，发现MSS的结论在使用降雨量水平作为工具时依然成立，但2000年后降雨与增长的关系减弱，需要寻找新的工具变量。
Miguel, Satyanath, and Ernest Sergenti (2004), henceforth MSS, show that economic growth is negatively related to civil conflict in Africa, using annual rainfall variation as an IV for growth. Antonio Ciccone (2011) argues that thanks to rainfall's mean-reverting nature, rainfall levels are preferable to annual changes. We make three points. First, MSS's findings hold using rainfall levels as instruments. Second, Ciccone (2011) does not provide theoretical justification for preferring rainfall levels. Third, the first-stage relationship between rainfall and growth is weaker after 2000, suggesting that alternative instruments are needed when studying recent conflicts. We highlight the accumulating microeconomic evidence that adverse economic shocks lead to political violence.