For a decade, economists have been fascinated by the phenomenon of open source software (OSS). OSS is marked by free access to the software and its source code. It is developed in a public, collaborative manner by thousands of non-paid volunteers as well as profit seeking firms. Today, OSS is...

Field experiments occupy a middle ground between laboratory experiments and naturally occurring field data. The idea is to perform a controlled experiment that captures important characteristics of the real world. Relative to traditional empirical economics, field experiments provide an...

We survey the literature on social networks by putting together the economics, sociological and physics/applied mathematics approaches, showing their similarities and differences. We expose, in particular, the two main ways of modeling network formation. While the physics/applied mathematics...

This paper surveys the recent literature on the political economy of the formation of international environmental agreements. The survey covers theoretical modelling approaches and empirical studies including experimental work. Central to our survey is the question how the political process...