Using a large administrate dataset covering the universe of phone calls and airtime transfers in a country over a four year period, we examine the pattern of adoption of airtime transfers over time. We start by documenting strong network effects: increased usage of the new airtime transfer...

We estimate the demand for a videocalling technology in the presence of both network effects and heterogeneity. Using a unique dataset from a large multinational firm, we pose and estimate a fully dynamic model of technology adoption. We propose a novel identification strategy based on...

We examine the role of network effects in the demand for pharmaceuticals at both the brand level and for a therapeutic class of drugs. These effects emerge when use of a drug by others conveys information about its efficacy and safety to patients and physicians. This can lead to herd behavior...

The literature on networks suggests that the value of a network is positively affected by the number of geographically dispersed locations it serves (the "network effect") and the number of its users (the "production scale effect"). We show that as a result a firm's expected time until adoption...

Two-sided platforms (2SPs) cater to two or more distinct groups of customers, facilitating value-creating interactions between them. The village market and the village matchmaker were 2SPs; eBay and Match.com are more recent examples. Other examples include payment card systems, magazines,...

The relationships between social networks and economic behavior have been well-documented. However, it is often difficult to distinguish between the role of information sharing and other features of a neighborhood, such as factors that are common to people of the same ethnicities or...

Most firms achieve perfective progress, incrementally improving commodities or productivity. But technological progress is concentrated in a few firms achieving metamorphic progress: forming or transforming industries with technological breakthroughs (e.g., biotechnology, lasers, semiconductors,...

In this paper we examine the importance of local spillovers such as network externalities and learning from others in the diffusion of home computers using data on 110,000 U.S. households in 1997. Controlling for many individual characteristics, we find that people are more likely to buy their...

This paper analyzes the role of social networks in the diffusion of knowledge and adoption of cultivation techniques, from trainees to the wider community, in the context of an extension project in Guinea-Bissau. In order to test for social learning, we exploit a detailed census of households...