The 2010 earthquake in Haiti has exposed the extreme vulnerability of a people living in a country where the state and the economy simultaneously fail to deliver. Haiti’s neighbor, the Dominican Republic, has witnessed several phases of strong economic growth since the 1870s and an encouraging transition towards democratic rule in the late 20^th century. How could this Caribbean island drift apart so profoundly? Capitalizing on decades of seminal scholarship in the neo-institutional tradition North, Wallis and Weingast (2009) have developed a new conceptual framework to explain different performance characteristics of societies through time. In this study we put the latest vintage of institutional theory to the test by taking it to the case of Hispaniola. We conclude that it captures the differing internal logic of the political economy in both countries quite well, but that it is of little use to understand the effect of external (international) relations on long term development.