We examine how the spatial and social proximity of inventors affects knowledge flows, focusing especially on how the two forms of proximity interact. We develop a knowledge flow production function (KFPF) as a flexible tool for modeling access to knowledge and show that the optimal spatial...

The success of non-pharmaceutical interventions to contain pandemics often depends greatly upon voluntary compliance with government guidelines. What explains variation in voluntary compliance? Using mobile phone and survey data, we show that during the early phases of COVID-19, voluntary social...

Based on recent theoretical developments I argue that the average level of human capital is a local public good. Cities with higher average levels of human capital should therefore have higher wages and higher land rents. After conditioning on the characteristics of individual workers and...

This paper identifies a new channel through which bankrupt firms impose negative externalities on non-bankrupt peers. The bankruptcy and liquidation of a retail chain weakens the economies of agglomeration in any given local area, reducing the attractiveness of retail centers for remaining...

The distribution of firms in space is far from uniform. Some locations host the most productive large firms, while others barely attract any. In this paper, I study the sorting of heterogeneous firms across locations and analyze policies designed to attract firms to particular regions...

Alfred Marshall argues that industrial agglomerations exist in part because individuals can" learn skills from each other when they live and work in close proximity to one another. An" increasing amount of evidence suggests that the informational role of cities is a primary reason for" their...

The degree of geographic concentration of individual manufacturing industries in the U.S. has declined only slightly in the last twenty years. At the same time, new plant births, plant expansions, contractions and closures have shifted large quantities of employment across plants, firms, and...

Faster technological progress has long been considered a key potential benefit of agglomeration. Physical proximity to others may help inventors adopt new ideas in their work by increasing awareness about which new ideas exist and by enhancing understanding of the properties and usefulness of...

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...