The aim of this volume is not to provide or test a single theory of informal global governance but rather to provide a set of analyses that speak to a common set of theoretical, empirical, and methodological questions. More broadly, the aim is to advance the emerging research agenda on informality in world politics. We conclude the volume by highlighting four productive avenues for future research on informality, based on the insights of the empirical chapters.

Understanding contemporary global governance requires a focus on informality. States increasingly govern through informal intergovernmental organizations, transnational public–private governance initiatives, and other informal institutions. Even within formal institutions, informal practices complement or override formal rules. And diverse informal groupings operate in the orbit of governance institutions, framing novel issues and placing them on policy agendas. We address these three aspects of informality – of, inside, and around global governance institutions. We first trace the nature and extent of the shift toward informal governance. We then consider a range of factors that may be driving the shift, drawing on major streams of International Relations (IR) theory; we treat these as candidate explanatory variables. Finally, we summarize the findings on those variables, and other theoretical insights, from the empirical chapters of this volume.

Transnational policy networks (TPNs) participate in global governance by formulating ideas and policy options around and through formal and informal intergovernmental organizations. They illustrate the third type of informal governance introduced in Chapter 1, informal governance that exists in the spaces around these institutions. TPNs are constituted by individuals who share a common expertise, a common technical language, and broadly shared normative concerns, but not a common institutional setting nor agreement on specific policy goals. This chapter contrasts TPNs with other institutional forms in the literature – advocacy networks, epistemic communities, transgovernmental networks, public–private partnerships, multistakeholder initiatives, and transgovernmental initiatives – and argues for their integrative advantages and ability to address individual agency and power. A heuristic case illustrates how a TPN functioned to create the Office of the Ombudsperson at the UN – securing rights protection for individuals targeted for UN sanctions – despite the initial opposition of all five Permanent Members of the Security Council. The chapter concludes with reflections on the potential benefits of applying the concept to other emergent policy domains.