We provide a new model that generates persistent performance differences amongst seemingly similar enterprises. Our model provides a mechanism whereby efficient incumbent rivals can give permission for an inefficient firm to exist in the presence of efficient entrants. We demonstrate that, in a...

"This paper empirically examines the effects of market size on producers' sizes in retail trade industries with many producers. A robust prediction of oligopoly theory is that larger markets are more competitive and have lower price-cost markups. Because producers in more competitive markets...