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,...

In this article we analyse the vast literature advancing explanations for the Japanese stagnation of the 1990s, using the Business-Cycle-Accounting approach proposed by V. Chari, P. Kehoe, and E. McGrattan. This methodology allows us to identify the most (and the least) promising types of...

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

We develop a simple Ramsey model with numerous Cournotian industries where entry generates an endogenous markup. The model produces two different regimes: a monopoly and an oligopoly one. We provide a rigorous study of non-smooth dynamics and we also analyse the global dynamics of the model,...

In this article I develop an imperfectly competitive dynamic general equilibrium model for a small open economy integrated in a monetary union. Here, the type of entry in the non-traded goods' sector affects fiscal policy effectiveness. Fiscal policy effectiveness is enlarged when aggregate...

New Keynesian general-equilibrium static models showed the fiscal multiplier is an increasing function of the degree of monopoly. Here, I develop a simple intertemporal model allowing us to study the steady-state role of optimal capital stock (and depreciation) in the fiscal policy transmission...

The cyclical behavior of markups is at the center of macroeconomic debate on the origins of business-cycle fluctuations and policy effectiveness. In theory, markups may fluctuate endogenously with the business cycle due to sluggish price adjustment or to deeper motives affecting the...

Markup cyclicality has been central for debating policy effectiveness and understanding business-cycle fluctuations. However, measuring the cyclicality of markups is as important as understanding the microeconomic mechanisms underlying that cyclicality. The latter requires measurement of...

This paper surveys the link between imperfect competition and the effects 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...