“…First, much is now known about which IPIs exist and about the similarities and differences in their institutional design (Alger and Kille, 2014; Cofelice, 2015, 2018; Cutler, 2001; De Puig, 2008; Habegger, 2005; Kissling, 2014; Winzen and Rocabert, 2021). Second, recent studies have given us in-depth knowledge of the reasons why IPIs are created and empowered (Cofelice, 2018; Grigorescu, 2015; Lenz, 2019; Lenz et al, 2019; Rocabert et al, 2019; Schimmelfennig et al, 2020; Verdoes, 2020; Winzen and Rocabert, 2021). Third, there are systematic explanations of why individual members of national parliaments engage with IPIs (Lipps, 2021; Malang, 2019; Wagner, 2013).…”