Search Intensity, Job Advertising, and Efficiency
证明，当企业和工人都在市场上相互搜索时，均衡失业率可能过高，因为双方都忽略了搜索的正外部性：匹配成功会减少一个搜索者，从而节省社会搜索成本。文章指出，在相当弱的搜索技术限制下，没有可行的工资率可以内化这种外部性。
This paper demonstrates that if both firms and workers search the other side of the market for job matches the equilibrium rate of unemployment is likely to be too high. Both sides ignore a positive externality of their search: when they establish a job match they remove from the market a job searcher, so they save society his search costs. I show that there is no feasible wage rate that can internalize this externality under fairly weak restrictions on the technology of search.