On the Inefficiency of Matching Models of Unemployment with Heterogeneous Workers and Jobs when Firms Rank their Applicants
In a circular matching model, firms rank their applicants and pick the best suited one. Job creation appears to lower the average output. As firms do not internalize this effect, jobs are too many in the laissez-faire equilibrium under the Hosios condition. Due to similar externalities firms' search intensities are too strong whereas workers' search intensities are too weak.