Brugemann, B. and Moscarini, G. (2010). Rent Rigidity, Asymmetric Information, and Volatility Bounds in Labor Markets Review of Economic Dynamics, 13:575--596.

Two thirds of US unemployment volatility is due to fluctuations in workers' job-finding rate. In search and matching models, aggregate productivity shocks generate such fluctuations: via inputs in the matching technology, they affect the rate at which workers and firms come into contact. Quantitatively, this mechanism has been found to be negligible in a calibrated textbook model, but also more than sufficient if wages are completely rigid. We study a weaker concept of rigidity based on worker rents (wages in excess of the value of unemployment). We show that volatility is subject to an upper bound if worker rents are weakly procyclical, thus at best rigid. Quantitatively, with Rent Rigidity, the mechanism accounts for at most 20% of the variance of the job-finding rate. In light of this result we reexamine the question whether asymmetric information on gains from trade amplifies fluctuations. We analyze a series of bargaining solutions, and conclude that asymmetric information at best makes rents rigid. Our analysis provides a unifying perspective on a very lively debate. {\textcopyright} 2009 Elsevier Inc.