New ideas, products, and practices take time to diffuse, a fact that is often attributed to some form of heterogeneity among potential adopters. This paper examines three broad classes of diffusion models -- contagion, social influence, and social learning -- and shows how to incorporate...

This paper investigates the role of social learning in the diffusion of a new agricultural technology in Ghana. We use unique data on farmers' communication patterns to define each individual's information neighborhood. Conditional on many potentially confounding variables, we find evidence that...

Recent developments in computer networks have driven the cost of distributing information virtually to zero, creating extraordinary opportunities for sharing product evaluations. The authors present pricing and subsidy mechanisms that operate through a computerized market and induce the...

If profit maximization is the objective of a firm, new information about quality should affect firm behavior only through its effects on market demand. I consider an alternate model in which suppliers are motivated by a desire to perform well in addition to profit. The introduction of quality...

We present a new framework to identify supply elasticities of storable commodities where past shocks are used as exogenous price shifters. In the agricultural context, past yield shocks change inventory levels and futures prices of agricultural commodities. We use our estimated elasticities to...

We conducted an experiment providing fertilizer grants to female rice farmers in Mali. We found that women who received fertilizer used both more fertilizer and more complementary inputs such as herbicides and hired labor. This shows that farmers respond to an increase in one input by...

The TseTse fly is unique to Africa and transmits a parasite harmful to humans and lethal to livestock. This paper tests the hypothesis that the TseTse reduced the ability of Africans to generate an agricultural surplus historically. Ethnic groups inhabiting TseTse-suitable areas were less likely...

Firms' incentives to manufacture biased user reviews impede review usefulness. We examine the differences in reviews for a given hotel between two sites: Expedia.com (only a customer can post a review) and TripAdvisor.com (anyone can post). We argue that the net gains from promotional reviewing...

I study a dynamic economy featuring adverse selection in asset markets. Borrowing-constrained entrepreneurs sell past projects to finance new investment, but asymmetric information creates a lemons problem. I show that this friction is equivalent to a tax on financial transactions. The implicit...