Crossnational statistical studies show a positive relationship between the length of time a country has been democratic and its economic performance. Old democracies grow faster, ceteris paribus, and also demonstrate advantages in some economic policies thought to be conducive to growth....

Any account of the social and economic conditions of democracy must come to terms with the central finding of the cross-national statistical research: a sturdy (though not perfect) association between economic development and democracy. To tackle these questions of causation, we adopted a...