This paper shows that the matching function and the Beveridge curve in the United States exhibit strong nonlinearities over the business cycle. These patterns can be replicated by enhancing a search and matching model with idiosyncratic productivity shocks for new contacts. Large negative...

There is strong empirical evidence for Cobb-Douglas matching functions. We show in this paper that this widely found relation between matches on the one hand and unemployment and vacancies on the other hand can be the result of different underlying mechanisms. Obviously, it can be generated by...

This paper proposes a new approach to evaluate the macroeconomic effects of the “Hartz IV” reform, which reduced the generosity of long-term unemployment benefits. We propose a model with different unemployment durations, where the reform initiates both a partial effect and an equilibrium...