Individuals form teams to produce an output. The quality and quantity of a team's output depends on the ability and the effort level of its members. The ability of individuals as well as their work ethic is however imperfectly known. In such an environment, individuals wishing to form a new team...

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...