This paper charts the evolution and diversification of trade in knowledge that has taken place in the quarter-century since the WTO TRIPS Agreement came into force. Entirely new markets have come into being, potentially redefining the very character of 'trade'.

This paper quantifies the extent of preferential trade as a share of total world trade in different regions of the world and for two periods. Results show that: i) preferential trade represented 40% of world trade in the period 1988-1992 and it slightly increased to 42% during the period 1993-1997;...