This note illustrates the fact that the number of active firms in free entry equilibrium may be largely indeterminate and different levels of positive profits may in many cases be sustained. This is shown to be true, in spite of market contestability, either under Cournot competition or under...

We study an endogenous business cycle model with Cournotian monopolistic competition and an endogenous number of firms in each sector. Our model is a simple general equilibrium macroeconomic model introducing overlapping generation both of consumers and firms. Firms strategically decide on...

The paper examines some issues linked to the integration of market power in general equilibrium. The first part reviews the different existing approaches: subjective and objective, in terms of quantities and in terms of prices. The second part presents a semi-competitive model, based on a sector...