Shock me like a Hurricane: how Hurricane Katrina changed Louisiana's formal and informal institutions
利用合成控制法，研究卡特里娜飓风对路易斯安那州正式制度（政府就业和财产税）与非正式制度（社会资本）的长期影响，发现飓风减少了公共部门规模，但对社会资本无显著影响。
Abstract Institutions matter for postdisaster recovery. Conversely, natural disasters can also alter a society's institutions. Using the synthetic control method, this study examines the effects that Hurricane Katrina (2005) had on the formal and informal institutions in Louisiana. As measures of formal institutions, we employ two economic freedom scores corresponding to government employment (GE) (as a share of total employment at the state-level) and property tax (PT). These measures serve as proxies for the level of governmental interference into the economy and the protection of private property rights respectively. To assess the impact on informal institutions, we use state-level social capital data. We find that Hurricane Katrina had lasting impacts on Louisiana's formal institutions. In the post-Katrina period, we find that actual Louisiana had persistently higher economic freedom scores for both GE and PT than the synthetic Louisiana that did not experience the hurricane. These findings imply that the hurricane led to a reduction in both PTs and GE, which indicates a decrease in the relative size of the public sector as a share of the state's economy. On the other hand, we find no impact on our chosen measure of informal institution.