a new theory.

It is well known that a monopolist selling a single good, say a painting, can extract higher rents running an auction-type mechanism rather than posting a fixed price. In competitive markets, for example selling used books on line, price posting is often more prevalent than auctions. While...

We consider a monetary economy with directed multilateral matching between buyers and sellers. A buyer chooses how much money to hold, observes the location of all sellers, and decides which seller to visit. The number of buyers that arrive at a particular seller is random due to lack of...

We develop and analyze a labor search model in which heterogeneous firms operate under decreasing returns and compete for labor by publicly posting long-term contracts. Firms achieve faster growth by offering higher lifetime wages that attract more workers which allows to fill vacancies with...

Trade effects the size of firms in the economy differentially. Exporting firms tend to become larger relative to non-exporting firms. This affects different workers in the economy differentially. We develop a two-sided matching model with heterogeneous firms and heterogeneous workers and firm...

We argue that using wage data alone, it is virtually impossible to identify whether Assortative Matching between worker and firm types is positive or negative. In standard competitive matching models the wages are determined by the marginal contribution of a worker, and the marginal...

the firms' market power.

We propose a rational theory of sexual behavior, where people explicitly take the risk of HIV infection into account. Risky sex has two margins: the use of condoms and engaging in extra-marital affairs. The model exhibits important general equilibrium effects since an increase in the overall...

We propose a model of directed search with multi-worker firms, and show its properties for the growth dynamics of firms and the market efficiency.

We analyze the efficiency properties of price posting in a market where sellers compete for the buyers' business. They key feature of the approach is to investigate price posting as an equilibrium outcome even if sellers can compete with other mechanisms. When buyers are homogeneous, we show...