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...

In this paper, the search model is proposed, in which homogeneous firms are uncertain about the job seekers' number of friends, who can help them in the job search (social capital). All workers have the same productivity and differ only in the social capital. A firm offers a take-it-or-leave-it...

While strong social ties help individuals cope with missing institutions, trade is essentially limited to those who are part of the social network. We examine what makes the decision to trust a stranger different from the decision to trust a member of a given social network (a friend), by...