Abstract Peacemaking often involves the submission of agreements to popular consultation to ensure legitimacy and popular support. However, this exposes these agreements to various factors influencing democratic processes, including weather conditions. We examine the role of exogenous factors, particularly weather, in shaping the outcome of peace referendums, focusing on the case of the 2016 Colombian peace referendum. President Juan Manuel Santos pledged to let the Colombian people decide on the agreement between the government and FARC. However, the unexpected rejection of the agreement by a slim margin raised questions about external influences, such as Hurricane Matthew striking the Colombian Caribbean coast during the referendum. Utilizing unique meteorological and electoral data, and a novel framework, we assess the impact of the hurricane on voter behavior and its potential to change the outcome. We find that while weather significantly reduced turnout (by 11% to 13%), it did not alter the referendum outcome. Our counterfactual analysis reveals that changing the result would have required either much larger turnout effects or systematically different preferences among missing voters than those observed. Our study highlights the importance and limitations of institutional design in peacemaking and democratic processes, especially in high-stakes elections seeking to end prolonged conflict. By exploring the interplay between weather, democratic participation, and institutional design, our research provides insights into broader issues of referendum-based preference aggregation as a decision-making mechanism.
Bernal et al. (Sun,) studied this question.