International Journal of Computational Economics and Econometrics

While there is a large pool of assured knowledge about various general dimensions of the structure and dynamics of innovation networks, several basic structural features deserve more attention in future research on network effects. Our contribution concentrates on three key structural characteristics: i) the type of actors; ii) contexts and (inter-) organisational environments of networks; iii) modes and contents of knowledge exchange. We discuss the role of these structural characteristics by using research material from an accompanying evaluation of the German 'Leading-Edge Clusters Competition'. Major results are: Innovation network actors are rather heterogeneous entities, stretching from highly complex organisations to single individuals. Networks are embedded in different sectoral, organisational and situational contexts. In many cases, even defining the boundaries of the relevant network is a challenge for innovation researchers. Knowledge exchange flows through different channels, and can be seen as a context-dependent combination of formal and tacit elements.