Legal traditions and the ratification of the Paris agreement

We study whether legal traditions matter for the propensity of countries to ratify the Paris Agreement (PA), and thus their level of cooperation on addressing climate change. On the one hand, the economics literature argues that civil law countries are generally more prone to intervene to address negative externalities. On the other hand, the international law literature argues that the legal traditions' compatibility with international agreements depends on their designs. While civil law countries prefer binding obligations within international agreements, common law countries prefer nonbinding obligations. To test these hypotheses, we use survival analysis to analyze the timing of the ratification of the PA by 175 countries. Crucially, the PA includes nonbinding obligations, particularly the emissions-cut pledges denoted as Nationally Determined Contributions. Our baseline estimate suggests that common law countries have a 71 % higher conditional probability of ratifying the PA than do civil law countries, supporting the international law hypothesis. This novel result holds up to a host of robustness checks and may help inform the design of future agreements. Moreover, we find some further support for the hypothesis based on international law from the Kyoto Protocol. For this agreement, in a subsample of Annex I countries with binding obligations, common law countries instead have a lower conditional probability of ratification.