In this paper we test the celebrated `Strength of weak ties' theory of Granovetter (1973). We test two hypotheses on the network structure in a data set of collaborating economists. While we find support for the hypothesis of transitivity of strong ties, we reject the hypothesis that weak ties...

We study the structure of pairwise stable networks from a very general point. Rather than assuming a particular functional form of utility, we simply assume that the society is homogeneous, i.e. that agents' utilities differ only with respect to their network position while their names do not...

In this paper, we present a formal framework of possible network formations among immigrants. After arriving in the new country, one of the new immigrant’s important decisions is with whom to maintain a link in the foreign country. We find that the behavior of the first two immigrants affects...

We study some recent developments and challenges in the empirics of the effects of social networks. We focus in particular on researchers' ability to make policy recommendations based on a standard linear econometric model. We examine the potential compatibility between this type of econometric...

A substantial number of studies have extended the work on universal properties in physical systems to complex networks in social, biological, and technological systems. In this paper, we present a complex networks perspective on interfirm organizational networks by mapping, analyzing and...

In all social and economic interactions, individuals or coalitions choose not only with whom to interact but how to interact, and over time both the structure (the “with whom”) and the strategy (“the how”) of interactions change. Our objectives here are to model the structure and...

High levels of clustering—the tendency for two nodes in a network to share a neighbor—are ubiquitous in economic and social networks across different applications. In addition, many real-world networks show high payoffs for nodes that connect otherwise separate network regions, representing...

This paper shows that the relationship between social networks and cooperative trading is a two-way street. The possibility of cooperative trading enforced by third-party sanctions provides players with incentives to form costly links, and investing in costly links increases the power of...

We study the criminal networks that will emerge in the long run when criminals are neither myopic nor completely farsighted but have some limited degree of farsightedness. We adopt the horizon-K farsighted set to answer this question. We find that in criminal networks with n criminals, the set...