When the mortality rate is high, repeated interaction alone may not sustain cooperation, and religion may play an important role in shaping economic institutions. This insight explains why during the fourteenth century, when plagues decimated populations and the church promoted the doctrine of...

We develop a theory of innovation for entry and sale into oligopoly, and show that an invention of higher quality is more likely to be sold (or licensed) to an incumbent due to strategic product market effects on the sales price. Preemptive acquisitions by incumbents are shown to stimulate the...

When will a monopolist have incentives to foreclose a complementary market by degrading compatibility/interoperability of his products with those of rivals? We develop a framework where leveraging extracts more rents from the monopoly market by "restoring" second degree price discrimination. In...

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...

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....

Exit of venture-backed firms often takes place through sales to large incumbent firms. We show that in such an environment, venture-backed firms have a stronger incentive to develop basic innovations into commercialized innovations than incumbent firms, due to strategic product market effects....

Employment growth is strongly predicted by smaller average establishment size, both across cities and across industries within cities, but there is little consensus on why this relationship exists. Traditional economic explanations emphasize factors that reduce entry costs or raise...

Why are some places more entrepreneurial than others? We use Census Bureau data to study local determinants of manufacturing startups across cities and industries. Demographics have limited explanatory power. Overall levels of local customers and suppliers are only modestly important, but new...

We study the effects of managerial practices in schools on students' outcomes. We measure managerial practices using the World Management Survey, a methodology that enables us to construct robust measures of management quality comparable across countries. We find substantial heterogeneity in...

Members of a patent pool agree to use a set of patents as if they were jointly owned by all members and license them as a package to other firms. Regulators favor pools as a means to encourage innovation: Pools are expected to reduce litigation risks for their members and lower license fees and...