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 nationally representative household data from the 2008 wave of the Rural to Urban Migration in China survey, nearly two thirds of rural-urban migrants found their employment through family members, relatives, friends or acquaintances. This paper investigates why the use of social network to...