This paper develops an oligopolistic model of international trade with heterogeneous firms and endogenous R&D to examine how trade liberalization affects firm and industry productivity, as well as social welfare. We identify four effects of trade liberalization on productivity: (i) a direct...

This paper generalizes the frequently used Hotelling model for two-sided markets in order to determine the equilibrium market shares. We show that advertisement levels depend neither on the media price nor on the location of the media firm. An increase in advertising revenues does not change...