中文摘要
本文提出了一个主权债务的连续时间模型。在该模型中,一个相对缺乏耐心的主权政府的隐藏类型在不能违约的承诺类型与可以违约的机会主义类型之间来回切换。我们假定,外部贷款人对承诺类型在任意给定的债务水平和债券价格下应如何借款持有特定信念。在任何马尔可夫均衡中,机会主义类型在借款时模仿承诺类型,仅通过在随机时点对其债务违约来揭示自身类型。该均衡具有一个“毕业日”:自上次违约起经过一段有限时间,声誉便达到最高水平,此后不违约不再影响声誉。在该日期之前,不违约总是会提高该国的声誉。对于近期违约过的国家,债券价格和债务总额均为距该国上次违约所经过时间的增函数。对于近期未违约的国家(即已经“毕业”的国家),债券价格保持不变。
Abstract
This paper presents a continuous‐time model of sovereign debt. In it, a relatively impatient sovereign government's hidden type switches back and forth between a commitment type, which cannot default, and an opportunistic type, which can, and where we assume outside lenders have particular beliefs regarding how a commitment type should borrow for any given level of debt and bond price. In any Markov equilibrium, the opportunistic type mimics the commitment type when borrowing, revealing its type only by defaulting on its debt at random times. The equilibrium features a “graduation date”: a finite amount of time since the last default, after which time reputation reaches its highest level and is unaffected by not defaulting. Before such date, not defaulting always increases the country's reputation. For countries that have recently defaulted, bond prices and the total amount of debt are increasing functions of the amount of time since the country's last default. For countries that have not recently defaulted (i.e., those that have graduated), bond prices are constant.