Effects of fairness principles on willingness to pay for climate change mitigation

Despite the shift from multilateral negotiations on legally binding mitigation commitments to the decentralized nonbinding Intended Nationally Determined Contributions (INDCs) approach in global climate policy, governments and other stakeholders continue to insist that fairness principles guide the overall effort. Key recurring principles in this debate are capacity and historical responsibility. To keep global warming within the internationally agreed 2 °C limit, many countries will have to engage in more ambitious climate policies relative to current INDCs. Public support will be crucial in this respect. We thus explore the implications of different fairness principles for citizens' preferences concerning burden sharing in climate policy. To this end, we implemented an online experiment in which participants (N = 414) played an ultimatum game. Participants were tasked with sharing the costs of climate change mitigation. The aim was to examine how participants' willingness to pay for mitigation was influenced by capacity and historical responsibility considerations. The results show that fairness principles do have a strong effect and that participants applied fairness principles differently depending on their position at the outset. It turns out that participants paid more attention to other players' capacity and historical responsibility when proposing a particular cost allocation and more attention to their own capacity and responsibility when responding to proposals by others. These and other findings suggest that framing climate policy in terms of internationally coordinated unilateral measures is likely to garner more public support than framing climate policy in terms of a global bargaining effort over the mitigation burden.