ABSTRACT

This study sheds light on possible spatial aggregation bias and mismeasurement in natural disaster impacts on economic growth when adopting the synthetic control method. Using the impacted US areas of Hurricane Katrina in 2005 as a case study, we compared trends of real GRDP per capita, population, and GRDP at New Orleans-Metairie metropolitan statistical area and Louisiana State, 1992–2017. This study empirically demonstrates that improper spatial units of analysis could distort the causal inference in the synthetic control method. Additionally, per capita growth as indicators of recovery from natural disasters is likely to misinterpret economic growth when affected regions experience a sharp decrease in population. These biased results arouse special attention to possible underestimation of natural disaster impacts, particularly when analysing economically lagging regions. Also, seemingly increasing per capita indicators do not always support evidence of creative destruction after natural disasters.

摘要

本研究揭示了采用综合控制方法时自然灾害对经济增长影响可能存在的空间聚集偏差和误测。我们以 2005 年受卡特里娜飓风影响的美国地区为案例研究，比较了 1992-2017 年新奥尔良-梅泰里大都会统计区和路易斯安那州的人均实际 GRDP、人口和 GRDP 趋势。这项研究从经验上证明，不恰当的空间分析单位可能会扭曲综合控制方法中的因果推理。此外，当受灾地区人口急剧减少时，作为自然灾害恢复指标的人均增长可能会误解经济增长。这些有偏见的结果引起了人们对可能低估自然灾害影响的特别关注，特别是在分析经济落后地区时。此外，看似增加的人均指标并不总是支持自然灾害后创造性破坏的证据。