Economic Geography Research Group

Fostering research in Economic Geography

Download Working Paper 02.09 (PDF, 227KB).

2009 Working Papers

Working Paper 02.09

The spatial dynamics of the inventor network in German biotechnology: geographical proximity versus triadic closure

Anne L.J. Ter Wal


This paper analyses the spatial dynamics of the inventor network in German biotechnology between 1970 and 1995, aiming to introduce a spatial dimension into the dynamic analysis of innovation networks. After a long-lasting phase of knowledge exploration biotechnology experienced a transition towards increasing knowledge exploitation in the late 1980s. We argue that this transition impacts on the dynamics of the inventor network. On the basis of a patent-based reconstruction of the inventor network and a stochastic estimation model of network evolution, this paper shows that geographical proximity between inventors is mostly relevant in a situation of knowledge exploration, when knowledge is predominantly tacit. By contrast, triadic closure gains relevance in a situation of knowledge exploitation, with higher levels of knowledge codification and the associated risk of unintended and costly knowledge leakages. Accordingly, triadic closure is becoming a more important driver of network dynamics over time.