In 2006 I started a PhD at Delft on the topic of Governance Structures of Free/Open Source Software under the supervision of Prof Michel van Eeten. This evolved into an empirical study of FreeBSD, a large free software operating system project, driven by the question whether modular product design, by mitigating coordination costs in the development process, increases the potential number of project contributors and has a positive effect on their labour productivity, because contributors can work independently of each other with little or no need for central coordination. In parallel with probing the effect of product structure on group dynamics, the study explored the emergence of governance in FreeBSD and looked at how it was affected by the historical increase of project scale.

I defended the PhD on 10 December 2012, whose findings are reported in the book that you can download here. The slides I used for the defense are here, my propositions are here and a summary of the main findings can be accessed here (a 1-page summary is also available).