We provide a simple explanation for the observation from the U.S. manufacturing sector that the job destruction rate fluctuates more than the job creation rate. In our model, proportional plant-level costs of creating and destroying jobs cause shrinking plants to be more sensitive to aggregate shocks than growing plants. We describe circumstances in which this microeconomic asymmetry is preserved in the aggregate and show that it can account for much of the observed asymmetries in gross job flows. This is so even though we abstract from job matching frictions, incomplete contracts, and aggregate congestion effects.

This paper extends the static analysis of oligopoly structure into an infinite-horizon setting with sunk costs and demand uncertainty. The observation that exit rates decline with firm age motivates the assumption of last-in first-out dynamics: An entrant expects to produce no longer than any incumbent. This selects an essentially unique Markov-perfect equilibrium. With mild restrictions on the demand shocks, sequences of thresholds describe firms' equilibrium entry and survival decisions. Bresnahan and Reiss' (1993) empirical analysis of oligopolists' entry and exit assumes that such thresholds govern the evolution of the number of competitors. Our analysis provides an infinite-horizon game-theoretic foundation for that structure.

Real Exchange Rate Fluctuations and the Dynamics of Retail Trade Industries on the U. S.-Canada Border by Jeffrey R. Campbell and Beverly Lapham. Published in volume 94, issue 4, pages 1194-1206 of American Economic Review, September 2004

This paper develops a simple model of firm entry, competition, and exit in oligopolistic markets. It features toughness of competition, sunk entry costs, and market-level demand and cost shocks, but assumes that firms' expected payoffs are identical when entry and survival decisions are made. We prove that this model has an essentially unique symmetric Markov-perfect equilibrium, and we provide an algorithm for its computation. Because this algorithm only requires finding the fixed points of a finite sequence of contraction mappings, it is guaranteed to converge quickly.