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'.

Using industry-level R&D and patent data for a sample of 29 countries for the period 2000-2008, we study the importance of international supply linkages for knowledge spillovers. We find a statistically significant effect of supply chains on international knowledge spillovers. We show that...