One important topic in my work is the analysis of patent citation networks. These networks are kind of special, because they are a-cyclical and directed (contrary to most other networks that economists analyze, which often contain cycles and are non-directed). This work started with a publication in Advances in Complex Systems, dealing with fuel cells. If you don't have access to this journal, you may download the paper here.

This methodology was further applied in a paper with Alessandro Nuvolari and Roberto Fontana in Economics of Innovation and New Technology in 2009 (direct download here) and in 2016 in a paper on regional dynamics (Journal of Economic Geography) with ├ľnder Nomaler (direct download here).

A paper taking a slightly different perspectives on patent citation networks was publised jointly with ├ľnder Nomaler in 2008, in Economics Systems Research (direct download here).