This article develops an empirical framework for analysing the timing of international treaties. A treaty is modelled as a dynamic game among governments that decide on participation in every period. The net benefit of treaty membership increases over time. Spillovers among members and non-members accelerate or delay treaty formation by transforming participation into a strategic complement or substitute, respectively. The predictions of the model inform the estimation of the structural parameters, based on a cross section of treaty ratification dates. With this approach, I estimate the sign and magnitude of strategic interaction in the ratification of the Montreal Protocol, in the formation of Europe's preferential trade agreements, and in the growth of Germany's network of bilateral investment treaties. Through a series of counterfactual experiments, I explore different mechanisms that give rise to strategic interaction in the formation of these treaties.

We study how the marginal welfare gain from increasing the unemployment insurance (UI) benefit level varies over the business cycle. We do this by estimating how the moral hazard cost and the consumption smoothing benefit of UI vary with labour market conditions, which we identify using variation in the interaction of UI benefit levels with the unemployment rate within U.S. states over time. We find that the moral hazard cost is procyclical, greater when the unemployment rate is relatively low. By contrast, we do not find evidence that the consumption smoothing benefit varies with the unemployment rate. We use these empirical results to estimate the marginal welfare gain, and we find that it is modest on average, but varies positively with the unemployment rate.

We study the relation between mechanism design and voting in public good provision. If incentive mechanisms must satisfy conditions of robust coalition-proofness as well as robust incentive compatibility, the participants' contributions to public good provision can only depend on the level of the public good that is provided and that level can only depend on the population shares of people favouring one level over another. For a public good that comes as a single indivisible unit the outcome depends on whether or not the share of votes in favour of provision exceeds a specified threshold. With more provision levels for the public good, more complicated mechanisms can be used but they still involve the counting of votes rather than any measurement of the participants' willingness to pay. The article thus provides a foundation for the use of voting mechanisms.