Recent uprisings in the Arab world consist of individuals revealing vastly different preferences than were expressed prior to the uprisings. This paper sheds light on the general mechanisms underlying large-scale social and institutional change. We employ an agent-based model to test the impact...

Online communities generate marketing value for both firms and consumers, and their sustainability relies on continuous user engagement. In an environment in which competition for engagement is fierce, digital platforms seemingly favor the use of negative emotion to engage users. Yet, the impact...

Biases in meeting opportunities have been recently shown to play a key role for the emergence of homophily in social networks (see Currarini, Jackson and Pin 2009). The aim of this paper is to provide a "simple" micro-foundation of these biases in a model where the size and type-composition of...

What explains the large variation in the number of contacts (degree) that different participants of social networks have: age, randomness, or some unobservable quality measure? The model presented in Jackson and Rogers (2007), which emphasizes age as the main source of variation, successfully...

This paper deals with the role of reciprocation in the formation of individuals' social networks, that is to what extent initiating a relation brings about its reciprocation. Following the activity of a panel of bloggers over more than a year, we seek to establish whether bloggers are mainly...

What motivates people in rural villages to share? We first elicit a baseline level of sharing using a standard, anonymous dictator game. Then using variants of the dictator game that allow for either revealing the dictator's identity or allowing the dictator to choose the recipient, we attribute...

The Web is the largest human information construct in history transforming our society. How can we understand, measure and model the Web evolution in order to design effective policies and optimize its social benefit? Early measurements of the Internet traffic and the Web graph indicated the...

This paper studies the effects of information exchange and social networks on the performance of prediction markets with endogenous information acquisition. We provide a game-theoretic framework to resolve the question: Can social networks and information exchange promote the forecast efficiency...

Information aggregation mechanisms are designed explicitly for collecting and aggregating dispersed information. An excellent example of the use of this "wisdom of crowds" is a prediction market. The purpose of our Twitter-based prediction market is to suggest that carefully designed market...

Which types of networks favor the diffusion of innovations in the sense that an innovation whose intrinsic benefits are greater than those of an established choice will be able to replace the latter when it is initially used only by a small fraction of a large population? For deterministic and...