In this paper, we demonstrate the efficiency of seller entry in a model of competing auctions in which we allow for both buyer and seller heterogeneity. This generalizes existing efficiency results in the competitive search literature by simultaneously allowing for nonrival (many-on-one)...

We analyse a model of equilibrium directed search in a large labour market. Each worker, observing the wages posted at all vacancies, makes a fixed, finite number of applications, a. We allow for the possibility of ex post competition should more than one vacancy want to hire the same worker....