A large literature describes how local risk sharing networks can help individuals smooth consumption in the face of idiosyncratic economic shocks.  However, when an entire community faces a large covariate shock, and when the transaction costs of transfers are high, these risk sharing networks...

Recent developments in mobile technologies have produced a new kind of device: a programmable mobile phone, the smartphone. In this article, the authors argue that the technological and social characteristics of this device make it a useful tool in social sciences, particularly sociology, social...

Crowdfunding is a fast emerging internet fundraising mechanism for soliciting capital from the crowd to support entrepreneurial ventures. This paper empirically investigates the dynamics of investors’ backing behaviors in the presence of network externalities and a finite time window. The...

Despite heated debate about the pros and cons of online physician ratings, very little systematic work examines the correlation between physicians’ online ratings and their actual medical performance. Using patients’ ratings of physicians at RateMDs.com and the Florida Hospital Discharge...

This paper proposes a revealed preference test of network formation models. Specifically, I consider network formation models where agents are (1) strategic, (2) externalities are confined to within an agent’s k-neighborhood, where k can be varied. I show that this model can be tested...

We develop a model of dynamic platform formation under positive platform externalities. Users can switch between an incumbent and entrant platforms, switching opportunities arise stochastically and users can choose whether to accept or reject an opportunity to switch. For homogeneous users, we...

While much is known about optimal design of auctions within the context of a single item for sale, little is known about optimal design of large platform markets like eBay and auto auction houses that house large numbers of concurrent auctions. We attempt a macro-level empirical market design...

Online labor markets are platforms that facilitate Buyer-Determined (BD) auctions in which buyers can identify and hire service providers who bid to offer IT services. We examine the effect of bid visibility (i.e., open bid versus sealed bid) on the bidders’ entry strategies (number of...

In developing countries with sparse retail banking branches, mobile telecom net- works have emerged as major providers of financial services bypassing traditional banks. Using individual-level mobile money transaction data in Tanzania, we find that the vast majority of these transactions can be...