We present a theory of spatial development. Manufacturing and services firms located in a continuous geographic area choose each period how much to innovate. Firms trade subject to transport costs and technology diffuses spatially across locations. The result is a spatial endogenous growth...

This paper proposes a simple theory of a system of cities that decomposes the determinants of the city size distribution into three main components: efficiency, amenities, and frictions. Higher efficiency and better amenities lead to larger cities, but also to greater frictions through...

In the last two decades the Indian economy has been growing unabatedly, with memories of the Hindu rate of growth rapidly fading. But this unprecedented growth has also resulted in widening spatial disparities. While cities such as Hyderabad have emerged as major clusters of high development,...

The trend toward ever greater urbanization continues unabated across the globe. According to the United Nations, by 2025 closes to 5 billion people will live in urban areas. Many cities, especially in the developing world, are set to explode in size. Over the next decade and a half, Lagos is...

We study how the sequential formation of free trade areas affects trade flows between member countries. In a three-country, three-good model of comparative advantage if two countries have an FTA, and both sign a similar agreement with the third, trade between the two decreases. However, if only...

This paper proposes a new method to measure ethnolinguistic diversity and offers new results linking such diversity with a range of political economy outcomes — civil conflict, redistribution, economic growth and the provision of public goods. We use linguistic trees, describing the...

This paper puts forth a unified theory of growth that captures a number of relevant features of countries’ transitions from stagnant, predominantly rural economies to vibrant, industrialized economies that have been overlooked by the literature. In our theory, increasing variety of consumer...

This paper proposes a novel mechanism whereby larger markets increase competition and facilitate process innovation. Larger markets, in the sense of more people or more open trade, support a larger variety of goods, resulting in a more crowded product space. This raises the price elasticity of...

We present a theory of spatial development. A continuum of locations in a geographic area choose each period how much to innovate (if at all) in manufacturing and services. Locations can trade subject to transport costs and technology diffuses spatially across locations. The result is an...