Why are good comparative studies of networks so rare? Practical lessons from a study on French clusters

French “competitiveness clusters” were set up in 2005 to strengthen cooperation between small and large enterprises, and training and research institutions working on similar topics and located in the same geographical area, with the aim of making this area more competitive and attractive through enhanced innovation. Our analysis of this set of about 70 apparently similar networks, on which much data were collected, has given us an opportunity to investigate the factors explaining the differences in their performance.