The Response of Mortgage Supply to Expected Flood Insurance Lapses
研究发现，当洪水保险费上涨（每年266美元）导致保险失效时，贷款机构会大幅提高抵押贷款拒绝率（增加0.49-0.81个百分点），远高于同等收入下降的影响，表明贷款机构将事后监控成本内化为事前信贷限制。
Abstract Flooding is among the costliest natural disasters in many countries. To protect collateral, many mortgage borrowers in the United States are legally required to maintain flood insurance. However, lax enforcement leads to frequent policy lapses. This paper shows that lenders provide credit contingent on borrowers’ insurance incentives. Exploiting exogenous premium rises ($266 annually) that disincentivize insurance take-up, I find mortgage denial rates dramatically increase by 0.49–0.81 pp. By comparison, lowering income by $266 has an effect of only 0.01 pp. Mortgage applicants’ composition remains unchanged, refuting demand-side explanations. Evidence suggests lenders internalize ex-post monitoring costs into ex-ante credit restrictions.