This PhD dissertation studies national similarities and differences in policy and regulation of public-private partnerships (PPPs), with an empirical focus on Denmark and Ireland. The starting point and motivation for the study is the observation that whereas PPPs are often depicted in the academic literature and in policy practice as a globally disseminated governance scheme, in reality, a closer examination of the PPP reform landscape reveals significant differences in national governments' PPP policy and regulation and in the amount of actually implemented PPP projects. By comparing the initiatives taken by the Irish government, which has embraced PPPs, with those of the Danish government, which has been a PPP sceptic, this study inquires into the fundamental questions as to how, why and to what consequences some governments have developed widespread policy and regulation frameworks to support the implementation of PPPs, whereas others have been much more reluctant. The dissertation addressed four research questions: (i) what are the key actors, strategies and institutions that create policies and regulations for the formation of PPPs?; (ii) how did governments' PPP policies and regulations develop over time, and how can their similarities and differences be explained?; (iii) how do differing national policy and regulation frameworks serve to facilitate or hinder the formation of PPPs, exemplified by four case studies from the schools sector?; (iv) what framework conditions does the EU set for PPP initiatives at national and sub-national levels?