“…They have become larger with respect to their member states and more encompassing with respect to the number of policy competencies (Panke et al, 2020). As a consequence of these developments, RIOs often share one or more members and are equipped with identical policy competencies and mandates at the same time, which we refer to as overlapping regionalism (OVREG) (Malamud, 2019;Nolte, 2018;Panke and Stapel, 2018a;Russo and Gawrich, 2017;Yeo, 2018). Case studies have demonstrated that overlaps between RIOs can carry negative consequences, such as an inefficient usage of RIO capacities and finances (Brosig, 2011;Hofmann, 2009Hofmann, , 2019, rivalry (Weiffen et al, 2013), member state non-compliance due to policy incompatibilities (Panke and Stapel, 2018b), or the diminished effectiveness of regional governance (Gebhard and Galbreath, 2013;Gómez-Mera, 2015).…”