The Dynamics of Enlargement in International Organizations

Abstract

Most international organizations (IOs) expand their membership over the course of their lifespan. Although these enlargements tend to be heralded as normatively positive-for the IOs themselves, for the new members, and for cooperative outcomes more generally-expansions can also lead to conflicts in the organization. What conditions lead to enlargement rounds that reshape an organization in unexpected ways? We argue that, depending upon the diversity of the initial group of countries, members may vote to admit new entrants that can tilt organizational decision-making in unexpected directions. We anticipate fewer enlargements with lesser impact on the character of the organization among organizations that have either a smaller range of founding members or a relatively even initial dispersion. We develop an agent-based model that accounts for the complex decision-making environment and social dynamics that typify IO accession processes. The model helps us explain how the nature of decision-making in organizations can shift following enlargement, likely changing the organization's output and goals.

Who joins counter-hegemonic IGOs? Early and late members of the China-led Asian Infrastructure Investment Bank

“…This is the case as only the first can borrow capital (the main good the AIIB intends to offer). Testing which countries had a higher probability of being admitted as regional or non-regional members is necessary insofar as the boundaries of regions are somewhat elastic (Gray et al, 2016: 5). For instance, the US-led ADB does not have any country located in the Middle East among its regional members, despite the fact that the Middle East is part of Asia.…”

“…IGOs with large membership gain from resource pooling and efficiency. The new organization and its leading state thus have an interest in attracting as many members as possible (Abbott and Snidal, 1998), even if, as Gray et al (2016) demonstrate, the diversity of views within IGOs (e.g., between democracies and autocracies) triggers instability in such institutions. Given that global institutions “…are engaged in a constant struggle to convince others of their legitimacy” (Barnett, 2015: 229), an expanding membership may however confer more acceptance and efficiency on IGOs (Gilligan, 2004).…”

Treaty Withdrawal and the Development of International Law

“…When preferences within institutions are more convergent, states can more easily negotiate and implement deeper forms of multilateral cooperation (Downs, Rocke and Barsoom, 1998;Gray, Lindstädt and Slapin, 2017;Davis, 2023). Exit removes an obstacle to cooperation.…”

New deals ‘The Second After Leaving?’ IO withdrawal and bilateral trade agreements

“…To define international organisations, we follow Pevehouse et al (2020: 494) in that institutions must be a formal entity, have at least three state members, and there is a permanent secretariat or other indication of institutionalisation. Coordination and collaboration through IOs (Gray et al, 2017; Pevehouse et al, 2020) can create substantial benefits for participating states, arguably the lowering of transaction costs being the most prominent advantage (Abbott and Snidal, 1998; Elsig et al, 2011; Hawkins et al, 2006; Mansfield and Pevehouse, 2006; Martin, 1992; Martin and Simmons, 1998; North, 1984; Schneider, 2011; Trommer, 2017). At the same time, joining IOs is not without costs as states must contribute financial resources or accept cuts into their decision-making power (Abbott et al, 2000; Fearon, 1998; Kahler, 2000; Simmons, 2010; Vaubel, 2006).…”