We study endogenous productivity in monopolistic competition with general (unspecified) utility/investment functions; a bigger investment yields smaller marginal cost. Then the equilibrium investments increase with the market size if and only if the utility (realistically) generates increasing...

In Russia the chain-stores gained a considerable market power. Our model combines a Dixit-Stiglitz industry with a monopolistic retailer. The questions addressed are: Does the retailer always deteriorate welfare, prices and variety of goods? Which market structure is worse: Nash or Stackelberg...