Present Bias in Politics and Self-Committing Treaties

We study how international agreements can take advantage of domestic time-inconsistency problems in the context of environmental policies. For example, policymakers will prefer future policies to be sustainable, but find it tempting to raise consumption when being in office. We find the equilibrium number of signatory countries to be higher than when preferences are time consistent, especially when the political environment is unstable and polarized, and the international spillovers are limited. In contrast to the traditional literature, the model can also explain why countries sign conventions with mandates that do not vary with the coalition size.