the firms' market power.

a new theory.

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...

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...