Acknowledgements
Many thanks to Mark Tewdwr-Jones, Charlotte Halpern, Stefanie Dühr and Joao Mourato for commenting on draft versions of this article and for pointing out relevant conceptual tools and references. Thanks to my former colleagues in the INTERREG IIIB NWE Programme for our initial discussions on the topic of INTERREG evaluation, in particular Philippe Doucet and his ideas on the ‘intensity of cooperation’, Monica Tanaka, Paul Stephenson and Daniel von Hugo. Thanks to John Zetter and the SAUL project partners in Frankfurt/Main for information related to the impact of the SAUL project.
Notes
1. In political science and organizational theory, isomorphism describes ‘the mechanisms leading one unit in a population to resemble other units facing the same set of environmental conditions’ (Radaelli, Citation2000, p. 40). DiMaggio and Powell (Citation1983) have analysed why organizations in a given field tend to become increasingly similar or homogeneous, and distinguish three analytical forms of ‘isomorphism’: ‘1) coercive isomorphism that stems from political influence and the problem of legitimacy; 2) mimetic isomorphism resulting from standard responses to uncertainty; and 3) normative isomorphism, associated with professionalization’ (p. 150).