Climate change mitigation requires international cooperation and for this cooperation to be sustainable over the long term, formal global agreements to reduce CO2 emissions need broad public support. Using data from an experimental conjoint survey, we provide estimates of the political demand for different types of climate agreements in France, Germany, the United Kingdom, and the United States. Specifically, we explore how three key dimensions of climate cooperation — costs and distribution, participation, and enforcement — affect demand for global climate agreements. We find that citizens’ sentiment toward climate agreements most strongly depends on costs. Our estimates imply that an increase of household costs equivalent to 0.5% of gross domestic product decreases the probability that an individual supports an agreement by 20% percent. Our results, however, also suggest that citizens are sensitive to the principles that govern the international distribution of costs, prefer more encompassing forms of climate cooperation, and support agreements that include a low sanction for failing emission reduction targets. Overall, our findings suggest that an important mechanism through which interests, norms, and institutions can support international cooperation is their influence on public opinion.

Contingent sovereign debt can create important welfare gains. Nonetheless, there is almost no issuance today. Using hand-collected archival data, we examine the first known case of large-scale use of state-contingent sovereign debt in history. Philip II of Spain entered into hundreds of contracts whose value and due date depended on verifiable, exogenous events such as the arrival of silver fleets. We show that this allowed for effective risk-sharing between the king and his bankers. The data also strongly suggest that the defaults that occurred were excusable – they were simply contingencies over which Crown and bankers had not contracted previously.