We show that in a search/matching model with endogenous participation in which workers are heterogeneous with respect to market productivity, satisfying the Hosios rule leads to excessive vacancy creation. The reason is that the marginal worker does not internalize the effect of his or her...

In this paper, we show how time-varying unemployment benefits can generate equilibrium wage dispersion in an economy in which identical firms post wages and homogeneous workers search for acceptable offers. We allow for matching frictions and for free entry and exit of vacancies, and we model...