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'...

In this paper, training, which is seen as a way to reduce the mismatch between workers and jobs, takes place on the job. We show that a general rise in unemployment lowers the probability of on-the-job training by reducing the mismatch. We then close the model by assuming free-entry and study...