Entry Regulations, Product Differentiation and Determinants of Market Structure

We use a dynamic oligopoly model of entry and exit to evaluate how entry regulations affect profitability and market structure in retail. The model incorporates demand and store-level heterogeneity. Based on unique data for all retail food stores in Sweden, we find that the average entry costs for small and large stores are 10 and 18 percent lower, respectively, in markets with liberal compared with restrictive regulations. Counterfactual simulations show that lower entry costs in restrictive markets result in higher entry rates and allow us to quantify the consequences of regulations in light of trade-offs between small and large stores

R&D Cooperatives and Market Collusion: A Global Dynamic Approach

We present a continuous-time generalization of the seminal R&D model of d’Aspremont and Jacquemin (American Economic Review, 1988) to examine the trade-off between the benefits of allowing firms to cooperate in R&D and the corresponding increased potential for product market collusion. We consider all trajectories that are candidates for an optimal solution as well as initial marginal cost levels that exceed the choke price. Firms that collude develop further a wider range of initial technologies, pursue innovations more quickly, and are less likely to abandon a technology. Product market collusion could thus yield higher total surplus