This paper introduces endogenous and directed technical change in a growth model with environmental constraints and limited resources. A unique final good is produced by combining inputs from two sectors. One of these sectors uses "dirty" machines and thus creates environmental degradation....

Public goods may exhibit complementarities that are essential for determining their individual value. Our results indicate that improving safety near parks can turn them from public bads to goods. Ignoring complementarities may lead to i) undervaluing the potential value of public goods; ii)...

The emergence of novelty, especially of new categories of people and organizations, is undertheorized in the social sciences. Some social worlds are more hospitable to novel introductions or exogenous perturbations than others. Explaining this relative "poisedness" is essential to understanding...

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...

We develop a new methodology for quantifying the tasks undertaken within occupations using over 3,000 verbs from more than 12,000 occupational descriptions in the Dictionary of Occupational Titles (DOTs). Using micro-data from the United States from 1880-2000, we find an increase in the...

Research on entrepreneurship often examines the local dimensions of new business formation. The local environment influences the choices of entrepreneurs; entrepreneurial success influences the local economy. Yet modern urban economics has paid relatively little attention to entrepreneurs. This...

Urban economics has traditionally viewed cities as having advantages in production and disadvantages in consumption. We argue that the role of urban density in facilitating consumption is extremely important and understudied. As firms become more mobile, the success of cities hinges more and...

We analyze a neoclassical general-equilibrium model to explain cross-metro variation in population, density, and land supply based on three amenity types: quality-of-life, productivity in tradables, and productivity in non-tradables. We develop a new method to estimate elasticities of housing...

New, “big” data sources allow measurement of city characteristics and outcome variables higher frequencies and finer geographic scales than ever before. However, big data will not solve large urban social science questions on its own. Big data has the most value for the study of cities when...

In an urbanizing world economy featuring thousands of cities, households and firms have strong incentives to make locational investments and self protection choices to reduce their exposure to new climate change induced risks. This pursuit of self interest reduces the costs imposed by climate...