We develop an overlapping generations model, where firms (as consumers) have a two-period life, investing in R&D during the first period and competing in the product market in the second period. The number of firms is endogenously determined and the set of successful firms by a Bernoullian...

Imperfect competition is a meaningful feature for macroeconomic analysis only to the extent that is leads to properties qualitatively different from those obtained under perfect competition. In particular, we have to wonder how imperfect competition per se may find an alternative fiscal policy....

A general notion of market perfect contestability is introduced. It coincides with the definition given by Baumol et al. under Bertrand competition, but is compatible with other forms of competition : Cournot competition as well as monopolistic competition. Using this notion, we illustrate the...

vVe analyse an overlapping generations economy with Cournotian monopolistic competition in the produced goods markets and perfect competition in the labour market. All prices are perfectly flexible and no adjustments costs are introduced. We show that these features lead to properties...

We examine two variants of the monopolistic competition model of Dixit and Stiglitz (1993). One is a simple general equilibrium model with n produced monopolistic goods and a numeraire good, the other in an "enlarged model", that includes labor time an an addiitonal good. In the case of alarge...

It is the study of the trade cycle during the thirties that made imperfectly competitive output markets a major theme in macroeconomics, principally under the lead of Harrod. Both him and Keynes were referring at the same time to a supposed feature of business cycles, namely the counter...

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 generations both of consumers and firms. Firms strategically decide on...

We present new conditions that guarantee the existence of mechanism with a unique or essentially unique equilibrium in auctions and public goods problems with semi-linear utility functions. These conditions bear only on the information structures of the agents

Properties of stochastic outcome functions are exploited to solve the moral hazard problem in teams under unobservable individual actions and different individual objectives. Two kinds of enforcement mechanisms are considered: Enforcement through utility transfers and enforcement through...