One reason for deadlock in international climate policy is disagreement over how to share the economic burden of greenhouse gas emission reductions. Countries disagree strongly on what criteria to use for structuring burden-sharing arrangements: historical or contemporary responsibility for emissions, economic capacity, vulnerability to climate change, or other. Complementing existing macro-level studies, I examine what criteria determine individuals’ perceptions of fairness in burden sharing. This bottom-up perspective is important because any effective international climate agreement will directly affect individuals (e.g. through energy taxes or other policies acting as behavioral constraints), and therefore requires domestic public support for successful implementation.
I conducted two interactive laboratory experiments where subjects reveal their fairness preferences through their behavior in an ultimatum game. A “proposer” suggests how to share the total mitigation cost between herself and a “responder”, who can either accept or reject the offer. If accepted, each subject pays her share from an initial endowment. If rejected, subjects run the risk of losing a large part of their endowment in a “climate catastrophe”. One experiment varies initial endowment and loss magnitude between proposers and responders to test the influence of economic capacity and climate change vulnerability on proposed cost distributions and acceptance rates. The other experiment examines the influence of historical responsibility; here subjects enter the ultimatum game with differing past emission levels determined in a prior “emissions game”.
Results indicate that all three criteria strongly affect individual fairness perceptions, but in different ways. While endowment inequalities make subjects more likely to propose and accept distributions where richer players pay substantially more, this effect is mitigated when vulnerability varies as well, with poorer and more vulnerable players more likely to propose and accept more unfavorable distributions. Differing historical emissions levels induce more skewed proposed distributions and lower overall acceptance rates.
