We develop a life-cycle model of the labor market in which different worker-firm matches have different quality and the assignment of the right workers to the right firms is time consuming because of search and learning frictions. The rate at which workers move between unemployment, employment...

We revisit the hypothesis that cyclical fluctuations in unemployment are caused by shocks to the discount rate. We use a rich search-theoretic model of the labor market in which the UE, EU and EE rates are all endogenous. Analytically, we show that an increase in the discount rate lowers the UE...

I study the equilibrium and the welfare effects of international trade when product markets are imperfectly competitive due of search frictions--as in Burdett and Judd (1983)--rather than product differentiation--as in Dixit and Stiglitz (1977). Markups are positive, even though there are...

As search frictions become smaller in the market for a consumer product, buyers are able to locate and access more sellers per unit of time. In response, sellers choose to design varieties of the product that are more specialized in order to exploit differences in the buyers' preferences. I find...

I study a version of the search-theoretic model of imperfect competition by Burdett and Judd (1983) in which sellers face a strictly increasing rather than a constant marginal cost of production. The equilibrium exists and is unique, and its structure depends on the extent of search frictions....

I derive a formula for the equilibrium distribution of markups in the search- theoretic model of imperfect competition of Butters (1977), Varian (1980), and Burdett and Judd (1983). The level of markups and the sign of the relationship between a seller's markup and its size depends on the extent...

I study a search equilibrium model of the labor market in which workers have stubborn beliefs about their labor market prospects, i.e. beliefs about their probability of finding a job and the wage they will earn that do not respond to aggregate fluctuations in fundamentals. I show that, when...

The effect of coworkers on the learning and the productivity of an individual is measured combining theory and data. The theory is a frictional equilibrium model of the labor market in which production and the accumulation of human capital of an individual are allowed to depend on the human...

We use a large dataset on retail pricing to document that a sizeable portion of the cross-sectional variation in the price at which the same good trades in the same period and in the same market is due to the fact that stores that are, on average, equally expensive set persistently different...

We propose a new business cycle theory. Firms need to randomize over firing or keeping workers who have performed poorly in the past, in order to give them an ex-ante incentive to exert effort. Firms have an incentive to coordinate the outcome of their randomizations, as coordination allows them...