论文标题
与时空数据的因果推断：估计空袭对伊拉克叛乱暴力的影响
Causal Inference with Spatio-temporal Data: Estimating the Effects of Airstrikes on Insurgent Violence in Iraq
论文作者
论文摘要
许多因果过程具有空间和时间维度。然而，当治疗和结果变量是由时空点过程产生的，经典的因果推理框架并不直接适用。我们通过将治疗点过程作为随机干预来扩展到这些环境的潜在结果框架。我们的因果估计包括在特定随机治疗策略下指定区域中预期的结果事件的预期数量。我们的方法允许任意空间溢出和时间结转效应的模式。使用Martingale理论，我们表明所提出的估计量是一致的，并且随着时间段增加的数量而渐近地正常。我们提出了一种敏感性分析，以实现未衡量的混杂因素的存在，并将其扩展到Hajek估计器。进行了仿真研究以检查估计器的有限样本性能。最后，我们通过估计2007年2月至2008年7月对美国空袭对伊拉克叛乱暴力行为的影响来说明拟议方法。我们的分析表明，增加每日空袭的平均数量最多一个月可能会导致更多的叛乱攻击。我们还发现一些证据表明，空袭可以将攻击从巴格达移动到最多400公里的新地点
Many causal processes have spatial and temporal dimensions. Yet the classic causal inference framework is not directly applicable when the treatment and outcome variables are generated by spatio-temporal point processes. We extend the potential outcomes framework to these settings by formulating the treatment point process as a stochastic intervention. Our causal estimands include the expected number of outcome events in a specified area under a particular stochastic treatment assignment strategy. Our methodology allows for arbitrary patterns of spatial spillover and temporal carryover effects. Using martingale theory, we show that the proposed estimator is consistent and asymptotically normal as the number of time periods increases. We propose a sensitivity analysis for the possible existence of unmeasured confounders, and extend it to the Hajek estimator. Simulation studies are conducted to examine the estimators' finite sample performance. Finally, we illustrate the proposed methods by estimating the effects of American airstrikes on insurgent violence in Iraq from February 2007 to July 2008. Our analysis suggests that increasing the average number of daily airstrikes for up to one month may result in more insurgent attacks. We also find some evidence that airstrikes can displace attacks from Baghdad to new locations up to 400 kilometers away
