One of the most prominent characteristics of multilateral organizations is that they do not “spring forth full blown”; they grow. Although this is well known, relatively few attempts have been made to explain it at a general level or to explore its implications. In this paper we show why states that desire to create a multilateral organization or agreement might be attracted to a strategy that involves admitting potential members sequentially based on their preferences. Such a “sequential construction” strategy can generate an unusual kind of structure-induced equilibrium that dramatically mitigates the breadth-depth trade-off and increases the level of cooperation a multilateral is able to attain. We evaluate these claims with data drawn from the history of the European Union and twenty environmental multilaterals.

Recent research on compliance in international regulatory regimes has argued (1) that compliance is generally quite good; (2) that this high level of compliance has been achieved with little attention to enforcement; (3) that those compliance problems that do exist are best addressed as management rather than enforcement problems; and (4) that the management rather than the enforcement approach holds the key to the evolution of future regulatory cooperation in the international system. While the descriptive findings above are largely correct, the policy inferences are dangerously contaminated by endogeneity and selection problems. A high rate of compliance is often the result of states formulating treaties that require them to do little more than they would do in the absence of a treaty. In those cases where noncompliance does occur and where the effects of selection are attenuated, both self-interest and enforcement play significant roles.