We develop a dynamic general equilibrium model of imperfect competition where a sunk cost of creating a new product regulates the type of entry that dominates in the economy: new products or more competition in existing industries. Considering the process of product innovation is irreversible,...

We consider a Ramsey model with a continuum of Cournotian industries where free entry generates an endogenous markup. The model produces two different regimes, monopoly and oligopoly, resulting in non-smooth dynamics. We analyze the global dynamics of the model, demonstrating the model may...

This paper surveys the link between imperfect competition and the e¤ects of fiscal policy on output, employment and welfare. We examine static and dynamic models, with and without entry under a variety of assumptions using a common analytical framework. We find that in general there is a robust...

We compute average mark-ups as a measure of market power throughout time and study their interaction with fiscal policy and macroeconomic variables in a VAR framework. From impulse-response functions the results, with annual data for a set of 14 OECD countries covering the period 1970-2007, show...

This note analyses a simple imperfectly competitive general equilibrium model where the entry mechanism generates an endogenous markup. In this second-best world fiscal policy is more effective than in Walrasian or in fixed-markup monopolistic competition models, as it produces efficiency gains...

In a recent article Chen et al. (2005) analyse the role of government expenditure in an imperfectly competitive static model, introducing a government-expenditure externality through the production function. Our purpose in the present paper is to argue that the claim from the authors that their...