A longstanding question in economics is why some countries are so much richer than others. Today, for example, income per capita in the worldÂ’s richest countries is roughly thirty-five times greater than it is in the worldÂ’s poorest countries. Recent work (e.g., Robert E. Lucas 2001, and...

AgricultureÂ’s share of economic activity is known to vary inversely with a countryÂ’s level of development. This paper examines whether extensions of the neoclassical growth model can account for some important sectoral patterns observed in a current cross-section of countries and in the...