中文摘要
关于抵押贷款违约，存在三种主流理论：策略性违约（由负资产驱动）、现金流违约（由负面生活事件驱动）和双重触发违约（两种负面触发因素均为必要条件）。这些理论一直难以比较，部分原因在于负面生活事件的测量存在误差。我们利用一组不存在策略性违约动机的借款人作为对照组，以处理这一测量误差。我们的核心发现是，在资不抵债的违约中，仅有6%完全由负资产单独造成，比此前的估计低一个数量级。随后，我们分析了其余的违约。我们发现，70%的违约仅由负面生活事件驱动（即现金流违约），而24%的违约由负面生活事件与负资产之间的交互作用驱动（即双重触发违约）。总体而言，这些结果提供了借款人违约背后各理论的完整分解，并表明负面生活事件发挥着核心作用。
Abstract
Abstract There are three prevailing theories of mortgage default: strategic default (driven by negative equity), cash flow default (driven by negative life events), and double-trigger default (where both negative triggers are necessary). It has been difficult to compare these theories in part because negative life events are measured with error. We address this measurement error using a comparison group of borrowers with no strategic-default motive. Our central finding is that only 6% of underwater defaults are caused exclusively by negative equity, an order of magnitude lower than previously thought. We then analyze the remaining defaults. We find that 70% are driven solely by negative life events (i.e., cash flow defaults), while 24% are driven by the interaction between negative life events and negative equity (i.e., double-trigger defaults). Together, the results provide a full decomposition of the theories underlying borrower default and suggest that negative life events play a central role.