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 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...