I develop a framework to explain why identity divides some communities and not others. An identity group is defined as a group of individuals with the same `culture'. A community is divided when different identities are socially segregated; a community is integrated when there is no social...

A key property of the World Wide Web is the possibility for firms to place virtually costless links to third-party content as a substitute or complement to their own content. This ability to hyperlink has enabled new types of players, such as search engines and content aggregators, to...

In this paper, I develop and estimate a dynamic model of strategic network formation with heterogeneous agents. The main theoretical result is the existence of a unique stationary equilibrium, which characterizes the probability of observing a specific network in the data. As a consequence, the...

To study how economic fundamentals affect the formation of social networks, a model is needed that (i) has agents responding rationally to incentives (ii) can be taken to the data. This paper combines game-theoretic and statistical approaches to network formation in order to develop such a...

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...

We analyze the linking and versioning strategies of a media firm when facing competition from blogs, search engines and news aggregators. First, we show that when the publisher competes against a blog it is less likely to release a “fighting version” if this generates significant spillovers...

Understanding the process of software adoption is of paramount importance to software start-ups. We study a monopolistic seller’s optimal consumer network structure formation (seeding, segmentation, sequencing, and pricing strategies) under network effects. We demonstrate the importance of...

One of the most salient issues faced by platforms like newspapers and credit card issuers is that users are heterogeneous in the value they bring to other users or to the platform. We develop a model with multi-dimensional heterogeneity where a monopoly platform chooses (price or non-price)...

This paper proposes approximate variational inference methods for estimation of a strategic model of social interactions. Players interact in an exogenous network and sequentially choose a binary action. The utility of an action is a function of the choices of neighbors in the network. I prove...