ADVERSE SELECTION, LEARNING, AND COMPETITIVE SEARCH
构建模型分析搜寻摩擦下时间对逆向选择的影响，发现企业调整合同所需时间越长，试用期内的低效过度工作越少，并得出最优试用期约一个月。
Abstract I develop a model that allows for an analysis of the effects of time on adverse selection in the presence of search frictions. I find that, as a firm takes longer to adjust a worker's contract in response to learning about his type, inefficient overwork during the time before wage adjustment (probation) decreases. This provides a rationale for an optimal (minimum) probation period of about one month in the baseline scenario. Optimal probation duration varies with the degree of search frictions, the cost of effort, the relative productivity of different types of workers, and minimum wage regulations.