Social interactions are considered pivotal to agglomeration economies. We explore a unique dataset on mobile phone calls to examine how distance and population density shape the structure of social interactions. Exploiting an exogenous change in travel times, we show that distance is highly...

Does the Internet undermine social capital or facilitate inter-personal and civic engagement in the real world? Merging unique telecommunication data with geo-coded German individual-level data, we investigate how broadband Internet affects several dimensions of social capital. One...

Does the Internet undermine social capital or facilitate inter-personal and civic engagement in the real world? Merging unique telecommunication data with geo-coded German individual-level data, we investigate how broadband Internet affects several dimensions of social capital. One...

Merchant guilds have been portrayed as “social networks“ that generated beneficial “social capital“ by sustaining shared norms, effectively transmitting information, and successfully undertaking collective action. This social capital, it is claimed, benefited society as a whole by...

This paper analyzes an early modern German economy to test alternative theories about guilds. It finds little evidence to support recent hypotheses arguing that guilds corrected market failures relating to product quality, training, and innovation. But it finds that guilds were social networks...

When workers send applications to vacancies they create a network. Frictions arise if workers do not know where other workers apply to (this affects network creation) and firms do not know which candidates other firms consider (this affects network clearing). We show that those frictions and the...

Government or company decisions on whom to hire are mostly delegated to politicians, public sector officials or human resources and procurement managers. Due to anti-corruption laws, agents cannot sell contracts or positions that they are delegated to decide upon. Even if bribing is ruled out,...

We present a multi-country theory of economic growth in which countries are connected by a network of mutual knowledge exchange. Knowledge in any country depends on the human capital of the countries it exchanges knowledge with. The diffusion of knowledge throughout the world explains a period...

We study the formation of networks in environments where agents derive benefits from other agents directly linked to them but suffer losses through contagion when any agent on a path connected to them is hit by a shock. We first consider networks with undirected links (e.g. epidemics,...

We study stable matchings on exogenously given or endogenously formed bipartite graphs that reflect constraints on matching. The effects of a change of the exogenously given graph (constraints) are investigated. Specifically, we examine to what extent individuals gain or lose from relaxing...