In some markets vertically integrated firms sell directly to final customers but also to independent downstream firms with whom they then compete on the downstream market. It is often argued that resellers intensify competition and benefit consumers, in particular when wholesale prices are...

This paper presents results from a calibrated welfare model of the UK mobile telephony market which includes many mobile networks; calls to and from the fixed network; networkbased price discrimination; and call externalities. The analysis focuses on the short-run effects of adopting lower...

This paper studies the role of structural remedies in merger control in a Cournot setting where (endogenous) mergers are motivated by prospective efficiency gains and must be submitted to an Antitrust Authority (AA) which might require partial divestiture for approval. Both positive and negative...

We present a tractable model of competition between an arbitrary number of interconnected communications networks in the presence of tariff-mediated network externalities, call externalities, and cost and market share asymmetries. On the theory side, we provide a criterion for stability in...

This paper studies the role of the failing firm defense (FFD) concept in merger control in a Cournot setting where: (i) endogenous mergers are motivated by prospective efficiency gains; and (ii) mergers must be submitted to an Antitrust Authority which might require partial divestiture for...

We show how size-contingent laws can be used to identify the equilibrium and welfare effects of labor regulation. Our framework incorporates such regulations into the Lucas (1978) model and applies this to France where many labor laws start to bind on firms with exactly 50 or more employees....

Models of product differentiation typically assume a demand for variety. This paper derives the demand for variety in a model where a representative consumer chooses how many specialised varieties to purchase for the pursuit of different activities. In contrast with previous models this...

This paper is motivated by the empirical regularity that industries differ greatly in the level of firm turnover, and that entry and exit rates are positively correlated across industries. Our objective is to investigate the effect of sunk costs and, in particular, market size on entry and exit...

This paper analyzes a model of capacity choice followed by price competition under demand uncertainty. Under various assumptions regarding the nature and timing of demand realizations, we obtain general predictions concerning the role of demand uncertainty on equilibrium outcomes. We show that...

This Paper introduces a simple extensive form pricing game. The Bertrand outcome is a Nash equilibrium outcome in this game, but it is not necessarily subgame perfect. The subgame perfect equilibrium outcome features the following comparative static properties. The more similar firms are, the...