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...

This experimental study investigates how behavior changes after punishment for an unkind action. It also studies how fairness perceptions affect the reaction to punishment and whether this effect is consistent across repeated play and role experiences. A repeated version of the power-to-take...

A symmetric network consists of a set of positions and a set of bilateral links between these positions. Examples of such networks are exchange networks, communication networks, disease transmission networks, control networks etc. For every symmetric network we define a cooperative transferable...

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...

This paper proposes a simple social network model of occupational segregation, generated by the existence of inbreeding bias among individuals of the same social group. If network referrals are important in getting a job, then expected inbreeding bias in the social structure results in different...

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...

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...

Trade opportunities are generally seen as valuable instruments to improve the allocation of resources in society. However, when the traded rights are secured through unproductive rent-seeking contests, the tradeability of the rents may provide stronger incentives to invest in rent-seeking...

Some committees are made up of experts, persons interested in both the (subject) matter at hand and in coming across as able decision-makers. Such committees would like to conceal disagreement from the public. We present a theory that describes the reaction of experts to the requirement to...