Economic Backwardness and Social Tension*
研究发现经济落后程度越高，爆发非暴力和暴力社会冲突的概率越大，并通过历史邮政和电报速度作为工具变量证实了因果关系。
Abstract We propose that relative economic backwardness contributes to the build‐up of social tension and non‐violent and violent conflict. We test our hypothesis using data on organized mass movements and armed civil conflict. The findings show that greater economic backwardness is consistently linked to a higher probability of onset of violent and especially non‐violent forms of civil unrest. We provide evidence that the relationship is causal in instrumental variables estimations using new instruments, including mailing speeds and telegram charges around 1900. The magnitude of the effect of backwardness on social tension increases in the two‐stage least‐squares estimations.