Is regionalism an increasing feature of the world economy?

Measuring the importance of regionalism in international trade is desirable but difficult. The number of regional trade agreements (RTAs) reported to the WTO or the proportion of world trade which is between countries in an RTA are frequently cited as evidence that regionalism is growing at an accelerating rate. This paper questions whether RTAs really are as important as the headline numbers suggest, or whether they just occupy an excessively large part of policymakers' and economic journalists' time. The main contributions are to analyse the number of RTAs and the share of world trade criteria in order to show why both are meaningless in the current world economy. The paper concludes that, although the extent of regionalism is difficult to measure and the desirability of individual RTAs is difficult to assess, the threat to the multilateral trading system does not appear to be as large as is often reported, because the long-term dynamics of RTAs lead either to state formation, which is important but rare, or to ineffectiveness, which is the fate of the vast majority of RTAs. © 2007 The Author Journal compilation © 2007 Blackwell Publishing Ltd.