It is unclear whether the hierarchy in the economics profession is the result of the agglomeration of excellence or of nepotism. I construct the professor-student network for laureates of and candidates for the Nobel Prize in Economics. I study the effect of proximity to previous Nobelists on...

We study the impact of bots on social learning in a social network setting. Regular agents receive independent noisy signals about the true value of a variable and then communicate in a network. They na¨ıvely update beliefs by repeatedly taking weighted averages of neighbors' opinions. Bots...

Impact evaluations of development programmes usually focus on a comparison of participants with a control group. However, if the programme generates externalities for non-participants such an approach will capture only part of the programme’s impact. Based on a unique large-scale quantitative...

Policy makers spend large amounts of public resources on the foundation of science parks and other forms of geographically clustered business activities, in order to stimulate regional innovation. Underlying the relation between clusters and innovation is the assumption that co-located firms...

I study a one-way flow connections model in which players are heterogeneous with respect to values and the costs of establishing a link. I first show that values and costs asymmetries are crucial in determining the level of connectedness of a network. Interestingly, unconnected equilibria are...

Many networks such as the Internet have been found to possess scale-free and small-world network properties reflected by so-called power law distributions. Scale-free properties evolve in large complex networks through self-organizing processes and more specifically, preferential attachment. New...

What determines remittances – altruism or enlightened self-interest - and do remittances trigger additional migration? These two questions are examined empirically in Egypt, Turkey and Morocco for households with family members living abroad. Results show, first, that one cannot clearly...

Many economic organizations have some relational structure, meaning that economic agents do not only differ with respect to certain individual characteristics such as wealth and preferences, but also belong to some relational structure in which they usually take different positions. Two examples...