The high degree of variance of crime rates across space (and across time) is one of the oldest puzzles in the social sciences (see Quetelet (1835)). Our empirical work strongly suggests that this variance is not the result of observed or unobserved geographic attributes. This paper presents a...

In many cases, aggregate data is used to make inferences about individual level behavior. If there are social interactions in which one person's actions influence his neighbor's incentives or information, then these inferences are inappropriate. The presence of positive social interactions, or...

Interest rate restrictions are among the most pervasive forms of economic regulations. This paper explains that these restrictions can be explained as a means of primitive social insurance. Interest rate limits are Pareto improving because agents borrow when they have temporary negative income...

In many countries, the operation of legal, political and regulatory institutions is subverted by the wealthy and the politically powerful for their own benefit. This subversion takes the form of corruption, intimidation, and other forms of influence. We present a model of such institutional...

Using a sample of Harvard undergraduates, we analyze trust and social capital in two experiments. Trusting behavior and trustworthiness rise with social connection; differences in race and nationality reduce the level of trustworthiness. Certain individuals appear to be persistently more...

We examine the relationship between urban characteristics in 1960 and urban growth (income and population) between 1960 and 1990. Our major findings are that income and population growth move together and both types of growth are (1) positively related to initial schooling, (2) negatively...

A large body of recent research argues that social, or non-market, interactions can explain a wide range of puzzling phenomena from fashion cycles to stock market crashes. This paper attempts to connect the range of these papers with a general model and a broad empirical overview. We establish...

A large body of recent research argues that social, or non-market, interactions can explain a wide range of puzzling phenomena from fashion cycles to stock market crashes. This paper attempts to connect the range of these papers with a general model and a broad empirical overview. We establish...

In many countries, the operation of legal, political and regulatory institutions is subverted by the wealthy and the politically powerful for their own benefit. This subversion takes the form of corruption, intimidation, and other forms of influence. We present a model of such institutional...

Recent theories of economic growth, including Romer (1986), Porter (1989) and Jacobs (1969), have stressed the role of technological spillovers in generating growth. Because such knowledge spillovers are particularly effective in cities, where communication between people is more extensive, data...