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 develop and analyze a tractable empirical model for strategic network formation that can be estimated with data from a single network at a single point in time. We model the network formation as a sequential process where in each period a single randomly selected pair of agents has the...