In the context of Caribbean small island jurisdictions, a picture has customarily been painted of bloated bureaucracies, the prevalence of state institutions in the mechanics of governance, institutional weakness and a lack of institutional innovation. We argue that particularistic claims about enduring institutional structures and behaviours have not come about in a vacuum. Our core contribution is toward Caribbean comparative scholarship from an institutional standpoint, whereby we utilize selected aspects of a constructivist theoretical framework, together with a Most Similar Systems Research Design. The findings and analysis are based on the triangulation of secondary data and primary data collected in 2015, via a series of elite interviews conducted in Curaçao and Sint Maarten, two Subnational Island Jurisdictions (SNIJs); and Trinidad and Tobago, an independent Small Island Developing State (SIDS). The primary thrust of our debate is to articulate the position that much of what obtains in public institutions in the Caribbean has been shaped by patterns of ideational diffusion and norm formation, which can be traced to colonial experiences. We grapple with this notion by exploring, inter alia, the sociopolitical heritage and continuity and change within the institutional structures of the named islands.