We consider research and development (R&D) investment competition between duopolistic firms that independently invest in two complementary technologies to produce their products. By "partially complementary technologies", we mean that each firm can produce the goods without both technologies but...

This paper formulates a reciprocal market model of international duopoly with network externalities to reconsider welfare effects of reductions in transport costs and tariffs. Depending on the magnitude of network externalities, we show two possibilities. One of them, which emerges under strong...

Constructing a duopoly model with non-constant marginal costs and a strict Pareto criterion, this paper examines welfare effects of world-price-fixing tariff reductions accompanied by adjustments of a domestic tax. If a destination-based consumption tax is used, this reform achieves a strict...