Modern theories of innovation often emphasize the role of the social context, including culture, in the process of innovation. This paper concentrates on the uses and roles of regional identity, which constitutes one of the forms of expression of a political culture, in the formation of public-private partnerships and in the launch of cluster policies since 1980 in Bavaria, Brittany, and the northeast of England. A comparative analysis shows that regional identity is a varied and modifiable resource for collective action, but with different uses and outcomes in each region.