We analyse R&D activity in transport and communication technology (TCRD), in a Cournot duopoly. Transport and communication costs are of the iceberg type, i.e., using up some portion of the product along its path to the final buyer. Firms invest in TCRD to increase the net amount of the product...

The existence of transport costs among countries makes pricesof tradables diverge. When the market structure is a differentiated oligopoly the prices of tradables increase as a country get larger and/orricher. In a framework of economies of scale-differentiation-monopolistic competition a less...