Climate engineering—the deliberate large-scale manipulation of the Earth’s climate system—is a set of technologies for reducing climate-change impacts and risks. It is controversial and raises novel governance challenges [T. C. Schelling, Climatic Change, 33, 303–307 (1996); J. Virgoe, Climatic Change, 95, 103–119 (2008)]. We focus on the strategic implications of solar geoengineering. When countries engineer the climate, conflict can arise because different countries might prefer different temperatures. This would result in too much geoengineering: the country with the highest preference for geoengineering cools the planet beyond what is socially optimal at the expense of the others—a theoretical possibility termed “free-driving” [M. L. Weitzman, Scand. J. Econ., 117, 1049–1068 (2015)]. This study is an empirical test of this hypothesis. We carry out an economic laboratory experiment based on a public “good or bad” game. We find compelling evidence of free-driving: global geoengineering exceeds the socially efficient level and leads to welfare losses. We also evaluate the possibility of counteracting the geoengineering efforts of others. Results show that countergeoengineering generates high payoff inequality as well as heavy welfare losses, resulting from both strategic and behavioral factors. Finally, we compare strategic behavior in bilateral and multilateral settings. We find that welfare deteriorates even more under multilateralism when countergeoengineering is a possibility. These results have general implications for governing global good or bad commons. Significance Governing climate change and other global commons is challenging. Climate engineering has recently gained attention as a way to manage climate risks. Solar geoengineering is a technology that allows countries to unilaterally influence the world temperature. Solar geoengineering could trigger conflicting interventions by countries who prefer different temperatures; economic theory suggests that countries wanting a cooler climate impose it on others. Other countries may react through countergeoengineering interventions. We study the governance of solar geoengineering using a laboratory experiment in which participants engage in a public good-or-bad game. Results confirm that too much geoengineering can occur, leading to considerable economic losses and increased inequality. The experiment also highlights unforeseen governance risks associated with such technologies.

We investigate the effect of exposure to refugees on locals’ preferences with regard to ethnic minorities using individual-level panel data from the Netherlands. The data combine self-reported preferences with administrative data on the residential locations of the locals and the refugees. The study period is marked by a sudden inflow of refugees in some neighbourhoods. We find that individuals living close to newly installed refugee facilities developed a more positive attitude towards ethnic minorities and became less supportive of anti-immigration parties compared to individuals living farther away. An investigation of mechanisms suggests that the local effect is due to contact between residents and refugees.

Understanding how to sustain cooperation in the climate change global dilemma is crucial to mitigate its harmful consequences. Damages from climate change typically occur after long delays and can take the form of more frequent realizations of extreme and random events. These features generate a decoupling between emissions and their damages, which we study through a laboratory experiment. We find that some decision-makers respond to global emissions, as expected, while others respond to realized damages also when emissions are observable. On balance, the presence of delayed/stochastic consequences did not impair cooperation. However, we observed a worrisome increasing trend of emissions when damages hit with delay

Distributional justice—measured by the proportionality between effort exerted and rewards obtained—and guilt aversion—triggered by not fulfilling others’ expectations—are widely acknowledged fundamental sources of pro-social behavior. We design three experiments to study the relevance of these sources of behavior when considered in interaction. In particular, we investigate whether subjects fulfill others’ expectations also when this could produce inequitable allocations that conflict with distributional justice considerations. Our results confirm that both justice considerations and guilt aversion are important drivers of pro-social behavior, with the former having an overall stronger impact than the latter. Expectations of others are less relevant in environments more likely to nurture equitable outcomes.