Payment Size, Negative Equity, and Mortgage Default
利用低利率环境下可调利率贷款还款额大幅下降的数据，研究发现月还款额减半可使违约风险降低约55%，且该效应在负资产借款人中同样显著。
This paper studies the treatment effect of monthly payment size on mortgage default, using a sample of adjustable-rate loans that experienced large payment reductions thanks to the recent low interest rate environment. Payment size has an economically large effect on repayment behavior; for instance, cutting the required payment in half reduces the delinquency hazard by about 55 percent. Importantly, the link between payment size and delinquency is equally strong for borrowers that are significantly underwater on their mortgage. Relying on payment reductions for identification circumvents the selection concerns due to prepayments that would be associated with rate increases.