The formation of new or geographically expanded regional trading arrangements is one of the dominant trends in the world economy. This paper reviews the changing nature of regional trading arrangements. In the 1980s and 1990s a new generation of arrangements has gone much beyond the removal of border‐trade barriers to the harmonization of non‐border instruments such as national subsidies and commodity taxes, standards, business law regulations and competition policy. They also, in some cases, cover service trade and factor trade. These extensions beyond the scope of traditional customs unions and free trade areas pose new questions about the meaning of regional integration. This paper proposes a new definition of regional integration in terms of price convergence and looks at the extent of regional integration in East A