We study the distribution of economic activity, as proxied by lights at night, across 250,000 grid cells of average area 560 square kilometers. We first document that nearly half of the variation can be explained by a parsimonious set of physical geography attributes. A full set of country...

In a series of papers, my colleagues and I have demonstrated that levels of per capita income, economic growth, and other economic and demographic dimensions are strongly correlated with geographical and ecological variables such as climate zone, disease ecology, and distance from the coast....

This paper addresses the complex relationship between geography and macroeconomic growth. We investigate the ways in which geography may matter directly for growth, controlling for economic policies and institutions, as well as the effects of geography on policy choices and institutions. We find...

We examine the evolution of market potential and its role in driving economic growth over the long twentieth century. Theoretically, we exploit a structural gravity model to derive a closed-form solution for a widely-used measure of market potential. We are thus able to express market potential...

The recruitment of foreign scientists enhances US science through an expanded workforce but could also cause harm by displacing better connected domestic scientists, thereby reducing localized knowledge spillovers. We develop a model in which a sufficient condition for the absence of overall...

Researchers have long hypothesized that spillovers from government, university, and private company R&D contribute to economic growth, but these contributions may be difficult to measure when they take a non-pecuniary form. The growth of networking devices and the Internet in the 1990s and 2000s...

We explore the determinants of research specialization across countries and its consequences for relative wages. Using a dynamic Ricardian model we examine the effects of faster international technology diffusion and lower trade barriers on the incentive to innovate. In the absence of any...

In many growth models, economic growth arises from people creating ideas, and the long-run growth rate is the product of two terms: the effective number of researchers and their research productivity. We present a wide range of evidence from various industries, products, and firms showing that...

This study examines the contribution of Chinese diaspora researchers – those born in China but working outside the country – to China's catching up in global science to become a world leader in research publications and citations. Using a novel name-based way to identify Chinese diaspora...

We explore the use of patent citations to measure the "basicness" and appropriability of inventions. We propose that the basicness of research underlying an invention can be characterized by the nature of the previous patents cited by an invention; that the basicness of research outcomes relates...