迁移、自选择与收入分配-来自中国城乡的证据

本文强调两个事实:第一,农村居民并非同质,他们根据自身的特征决定迁移与否;第二,那些成功地改变了户籍身份的永久移民与没能改变户籍身份的临时移民之间有着显著的差异。利用2002年的CHIP数据发现,永久移民的正选择效应非常明显,它使得农村地区教育水平较高、处于收入分布较高位置的样本减少。这导致农村的收入水平和农村内部的不平等程度降低,阻碍了城乡差距的降低。相反,临时移民的选择效应几乎可以忽略不计。     

Adverse selection when loss severities differ: First-best and costly equilibria

With information asymmetry between contracting parties, adverse selection may result. A separation may be achieved if low-risk types can signal their identity—for example, by selecting from a menu of price-quantity contracts. In such models, signaling is costly and solutions are, at best, second best. These models characterize risk types by differences in the probability, rather than in severity, of the costs they impose. However, when severity differences also are considered, first best solutions become feasible. We identify the circumstances in which costly separating equilibria prevail and those in which full-information equilibria can be attained.