This chapter reviews academic research on the connections between agglomeration and innovation. We first describe the conceptual distinctions between invention and innovation. We then describe how these factors are frequently measured in the data and some resulting empirical regularities....

Recent literature notes that when quality is produced with fixed costs, a high quality firm can undercut its rival's prices and may find it profitable to invest more in quality as market size grows large. As a result, a market can remain concentrated even as it grows large. When quality is...

When a product's product provision entails fixed costs, it will be made available only if a sufficient number of people want it. Some products are produced and consumed locally, so that provision requires not only a large group favoring the product but a large number nearby. Just as one has an...

We model spatial clusters of similar firms. Our model highlights how agglomerative forces lead to localized, individual connections among firms, while interaction costs generate a defined distance over which attraction forces operate. Overlapping firm interactions yield agglomeration clusters...

We use data from credit report and deeds records to better understand the extent to which second liens contributed to the housing crisis by allowing buyers to purchase homes with small down payments. At the top of the housing market second liens were quite prevalent, with as many as 45 percent...

This paper examines the impact of residential foreclosures and vacancies on violent and property crime. To overcome confounding factors, a difference-in-difference research design is applied to a unique data set containing geocoded foreclosure and crime data from Pittsburgh, Pennsylvania....

This paper surveys recent literature examining the relationship between environmental amenities and urban growth. In this survey, we focus on the role of both exogenous attributes such as climate and coastal access as well as endogenous attributes such as local air pollution and green space. A...

Historical city growth, in the United States and worldwide, has required remarkable transformation of outdated durable buildings. Private land-use decisions may generate inefficiencies, however, due to externalities and various rigidities. This paper analyzes new plot-level data in the aftermath...

We use detailed micro data to document a causal response of local retail price to changes in house prices, with elasticities of 15%-20% across housing booms and busts. Notably, these price responses are largest in zip codes with many homeowners, and non-existent in zip codes with mostly renters....

Understanding the forces that lead to correlations between pollution exposure, poverty, and race is crucial to the formation of sound environmental justice (EJ) policy. In particular, what are the roles of disproportionate siting of pollution sources versus post-siting housing market dynamics...