In addition to the usual problems of resolving disputes in commercial transactions, international transactors face the additional problem of enforcing judgments against trading partners who reside in another jurisdiction.  Created in 1958, the New York Convention on the Recognition and Enforcement of Foreign Arbitral Awards (NYC) seeks to bridge this enforcement gap by committing signatory countries to use state enforcement mechanisms to support private arbitral agreements. Although 144 countries have ratified the treaty, many countries delayed joining the NYC for decades despite what appear to be substantial benefits to membership.  This paper explores the factors affecting countries’ decisions to join the NYC and then analyzes empirically the membership timing decisions of the 144 members of NYC, from inception through January 2009.  Preliminary findings indicate that the benefits of membership rise with the participation of trade partners and neighbors and that speed of joining is related to the responsiveness of a country’s political system: Democracies on average join earlier, with parliamentary democracies joining sooner than presidential systems.  Accounting for the endogeneity of NYC membership decisions permits a reevaluation of the effects of membership on the volume and mix of countries’ international trade flows. It also allows a reevaluation of countries' participation in other international arrangements like the World Trade Organization(WTO).