This paper analyzes strategy-proof collective choice rules when individuals have single-crossing preferences on a finite and ordered set of social alternatives. It shows that a social choice rule is anonymous, unanimous, and strategy-proof on a maximal single-crossing domain if and only if it is...

In this paper we show that a homogeneous-product market with multiple Bertrand equilibria becomes a market with a single Bertrand equilibrium when we introduce a small degree of product differentiation. When differentiation tends to zero, that Bertrand equilibrium converges to the unique...

This paper is about a model of Bertrand competition in a homogeneous-good market with free entry of identical firms and variable returns to scale. If the optimum number of active firms in the market is two or more, and the number of active firms is equal to that optimum number, then Bertrand...

This paper develops a model for demand-system estimations, whose coefficients are own-price Marshallian elasticities and elasticities of substitution between goods. The model satisfies the homogeneity, symmetry and, eventually, adding-up restrictions implied by consumer theory, and is primarily...

We present a two-firm model of predation under complete information, based on different discount factors, and integrate it with a model of collusion. Competition, collusion and predation are seen as alternative strategies. The basic conclusions are that there is predation when one firm has a...