“…Most of these studies have focussed on the effectiveness of single institutions, often within larger comparative projects (e.g., Gupta and Falkner, 2006;Haas et al, 1993;Keohane and Levy, 1996;Miles et al, 2002;Victor et al, 1998;Young, 1997;Young et al, 1999). More recently, the increasing number and scope of international environmental institutions has led to new research on their interaction, for example in studies on regime interlinkages, regime 'clusters' or regime 'complexes' (van Asselt et al, 2005;Chambers, 2001;Oberthu¨r and Gehring, 2006;Rosendal, 2001a, b;Stokke, 2000;Velasquez, 2000). Institutional interplay is also one of the three research themes of the Institutional Dimensions of Global Environmental Change project of IHDP (Institutional Dimensions of Global Environmental Change Project, 1999;Young, 2002; on IDGEC and interplay see Schro¨der, forthcoming).…”