A large fraction of Uganda's population continues to earn a living from quasi-subsistence agriculture. This paper uses a static general equilibrium model to explore the relationships between high transportation costs, low productivity, and the size of the quasi-subsistence sector. We...

Income differences across countries primarily reflect differences in total factor productivity (TFP). More disaggregated data show that the TFP gap between rich and poor countries varies systematically across industrial sectors of the economy: Poor countries are particularly unproductive in...

Whether or not the marginal product of capital (MPK) differs across countries is a question that keeps coming up in discussions of comparative economic development and patterns of capital flows. Attempts to provide an empirical answer to this question have so far been mostly indirect and based...

The U.S. went through a remarkable structural transformation between 1800 and 2000. In 1800 the majority of people worked in agriculture. Barely anyone did by 2000. What caused the rapid demise of agriculture in the economy? The analysis here concentrates on the development of new consumer goods...

According to national accounts data, value added per worker is much higher in the non-agricultural sector than in agriculture in the typical country, and particularly so in developing countries. Taken at face value, this "agricultural productivity gap" suggests that labor is greatly misallocated...

We construct and calibrate a model of the world economy in which countries' opportunities to develop depend on their trade with advanced economies. Trade opportunities in turn depend on the relative population of the advanced and developing world. As developing countries become advanced, they...

Research and development (R&D) is a key determinant of long run productivity and welfare. A central issue is whether a decentralized economy undertakes too little or too much R&D. We develop an endogenous growth model that incorporates parametrically four important distortions to R&D: the...

We examine how economic stratification affects inequality and growth over time. We study economies where heterogenous agents interact through local public goods or externalities (school funding, neighborhood effects) and economy-wide linkages (complementary skills. knowledge spillovers). We...

This paper evaluates optimal public investment and fiscal policy for countries characterized by limited tax and debt capacities. We study a non stochastic CRS endogenous growth model where public expenditure is an input in the production process, in countries where distortions and limited...