Although economists generally agree that countries can derive substantial gains from international economic integration, the extent to which they should open themselves to international capital flows remains a controversial issue. There is still, 20 years after the rise of emerging markets finance, a wide diversity of approaches to capital account policies. Some emerging market economies maintain a completely open capital account. Others, most notably Brazil, have experimented more actively with market-based prudential capital controls since the crisis. And still other countries, such as China, maintain tight restrictions on their capital account. There has also been a shift in official views on this topic, which have become more sympathetic to capital controls (Ostry et al. 2011; IMF 2011). Unlike for trade in goods, however, there are no international rules to constrain, discipline, or indeed legitimise restrictions that countries put on their capital account.1 In our monograph Who Needs to Open the Capital Account? (Jeanne et al. 2012), we present the case for developing international rules for capital flows.