We study how policy choice and political selection are affected by the concentration of political power. In a setting with inefficient policy gambles, variations in power concentration give rise to a trade-off. On the one hand, power-concentrating institutions allocate more power to the voters' preferred candidate. On the other hand, they induce the adoption of more overly risky policies and decrease the voters' capability to select well-suited politicians. We show that full concentration of power is optimal if and only if the conflict of interest between voters and politicians is small. Otherwise, an intermediate level of power concentration is optimal.

Discourse analyses and expert interviews about climate engineering (CE) report high levels of reflectivity about the technologies' risks and challenges, implying that CE experts are unlikely to display moral hazard behaviour, i.e. a reduced focus on mitigation. This has, however, not been empirically tested. Within CE experts we distinguish between experts for radiation management (RM) and for carbon dioxide removal (CDR) and analyse whether RM and CDR experts display moral hazard behaviour. For RM experts, we furthermore look at whether they agree to laboratory and field research, and how they perceive the risks and benefits of one specific RM method, Stratospheric Aerosol Injection (SAI). Analyzing experts' preferences for climate-policy options, we do not find a reduction of the mitigation budget, i.e. moral hazard, for RM or CDR experts compared to climate-change experts who are neither experts for RM nor for CDR. In particular, the budget shares earmarked for RM are low. The perceptions of risks and benefits of SAI are similar for RM and climate-change experts. Despite the difference in knowledge and expertise, experts and laypersons share an understanding of the benefits, while their perceptions of the risks differ: experts perceive the risks to be larger. Key policy insights Experts surveyed all prioritize mitigation over carbon dioxide removal and in particular radiation management. In the views of the experts, SAI is not a viable climate policy option within the next 25 years, and potentially beyond, as global field-testing (which would be a precondition for long-term deployment) is widely rejected. In the case of SAI, greater knowledge leads to increased awareness of the uncertainty and complexity involved. Policy-makers need to be aware of this relationship and the potential misconceptions among laypersons with limited knowledge, and should follow the guidelines about communicating risks and uncertainties of CE that experts have been advised to follow.

Climate engineering (CE) and carbon capture and storage are controversial options for addressing climate change. This study compares public perception in Germany of three specific measures: solar radiation management (SRM) via stratospheric sulphate injection, large-scale afforestation, and carbon capture and storage sub-seabed (CCS-S). In a survey experiment we find that afforestation is most readily accepted as a measure for addressing climate change, followed by CCS-S and lastly SRM, which is widely rejected. Providing additional information decreases acceptance for all measures, but their ranking remains unchanged. The acceptance of all three measures is especially influenced by the perceived seriousness of climate change and by trust in institutions. Also, respondents dislike the measures more if they perceive them as a way of shirking responsibility for emissions or as an unconscionable manipulation of nature. Women react more negatively to information than men, whereas the level of education or the degree of intuitive vs reflective decision making does not influence the reaction to information.POLICY RELEVANCECurrent projections suggest that the use of climate engineering (CE) technologies or carbon capture and storage (CCS) is necessary if global warming is to be kept well below 2 degrees C. Our article focuses on the perspective of the general public and thus supplements the dialogue between policymakers, interest groups, and scientists on how to address climate change. We show that in Germany public acceptance of potentially effective measures such as SRM or CCS-S is low and decreases even more when additional information is provided. This implies that lack of public acceptance may turn out to be a bottleneck for future implementation. Ongoing research and development in connection with CCS-S and SRM requires continuous communication with, and involvement of, the public in order to obtain feedback and assess the public's reservations about the measures. The low level of acceptance also implies that emission reduction should remain a priority in climate policy.

This article analyzes determinants of technology acceptance and their interdependence. It highlights the role of affect in attitude formation toward new technologies and examines how it mediates the influence of stable psychological variables on the technology's acceptability. Based on theory and previous empirical evidence, we develop an analytical framework of attitude formation. We test this framework using survey data on attitudes toward stratospheric aerosol injection (SAI), a technology that could be used to counteract global warming. We show that affect is more important than risk and benefit perception in forming judgment about SAI. Negative and positive affect directly alter the perception of risks and benefits of SAI and its acceptability. Furthermore, affect is an important mediator between stable psychological variables—such as trust in governmental institutions, values, and attitudes—and acceptability. A person's affective response is thus guided by her general attitudes and values.

Stratospheric aerosol injection (SAI) is a climate engineering method that is reputed to be very effective in cooling the planet but is also thought to involve major risks and side effects. As a new option in the bid to counter climate change, it has attracted an increasing amount of research and the debate on its potential gained momentum after it was referred to in the 5th IPCC assessment report (IPCC 2013). One major objection to SAI and the research done on it is that it could undermine commitment to the mitigation of greenhouse gases. Policymakers, interest groups or individuals might wrongly perceive SAI as an easy fix for climate change and accordingly reduce their mitigation efforts. This is the first study to provide an empirical evaluation of this claim for individuals. In a large-scale framed field experiment with more than 650 participants, we provide evidence that people do not back-pedal on mitigation when they are told that the climate change problem could be partly addressed via SAI. Instead, we observe that people who have been informed about SAI mitigate more than people who have not. Our data suggest that the increase is driven by a perception of SAI as potential threat.

Injecting sulfate aerosols into the stratosphere could quickly offset global warming caused by anthropogenic greenhouse gas emissions. Because the technology would have global side effects, it raises not only technological but also political, ethical, and social concerns. Therefore, research on sulfate injection should be accompanied by a global debate that incorporates public perceptions and concerns into the development and governance of the technology. Our paper provides insight into public perceptions and explores their underlying patterns using a survey conducted in Germany. The data reveal a differentiated picture. Laboratory research on sulfate injection is broadly approved, whereas field research is much less approved. Immediate deployment is largely rejected. The acceptance of the technology is associated with the belief that climate change is a serious problem and that humans will eventually be able to control nature. It is also determined by the levels of trust in scientists and firms. Among the strongest objections against the technology is the belief that humans should not manipulate nature in the way injecting sulfate would. The actual public perceptions of sulfate injection will, however, evolve along with the ongoing debate between the public, experts, and policymakers.

Solar radiation management (SRM) could quickly offset global warming caused by anthropogenic greenhouse gas emissions. Because SRM would have global side effects, it raises not only technological but also political and social concerns. Therefore, SRM research should be accompanied by a global debate that incorporates public perception and concerns into the development and governance of the technology. Our paper provides insight into public perception and explores its underlying patterns using a survey conducted in Germany. The data reveal a differentiated picture. Laboratory research on SRM is broadly approved, whereas field research is much less approved. Immediate deployment is largely rejected. The acceptance of the technology is associated with the belief that climate change is a severe problem and that humans will eventually be able to control nature. It is also determined by the levels of trust in scientists and firms. Among the strongest objections against the technology is the belief that humans should not manipulate nature in the way SRM would. The actual public perception of SRM will, however, evolve along with the ongoing debate between the public, experts, and policymakers.

Climate engineering (CE) and carbon capture and storage sub-seabed (CCS-S) are currently controversially debated options to address climate change. Our paper provides empirical evidence on the public perception of two different CE measures, namely, stratospheric sulphate injection (SSI) and afforestation, as well as CCS-S. Using data from a novel large-scale survey, we analyse the determinants of acceptance of these measures in Germany. We also provide experimental evidence on how additional information on these measures changes the respondents’ acceptance. We show that the acceptance differs strongly between the three measures. Afforestation is strongly favoured over CCS-S and SSI. This ranking holds independent of the amount of information provided. For all three measures, we find that, on average, additional information decreases acceptance. However, the sign and the strength of the information effect strongly depend on personal characteristics, such as gender and risk attitude.

Firms increasingly tie charitable donations to their products, offer green products, or apply fair trade practices. We analyze consumer valuation for such products that combine characteristics of both public and private goods. In a laboratory experiment, subjects may purchase a private and a public good either separately or in the form of a bundle. The data show superadditivity for bundles of public and private goods, i.e., the willingness to pay for the bundle exceeds the willingness to pay for the two separate goods. By contrast, we find no superadditivity in control treatments with private goods only. We discuss several behavioral concepts in line with our results, as well as implications for fundraisers and firms.

We propose a simple mechanism that might improve voluntary contributions to public goods. Using a laboratory experiment we analyze how bundling public with private goods affects individuals’ valuations for both goods. In the experiment, subjects may purchase a private and a public good either separately or in the form of a bundle. The data show superadditivity for bundles of public and private goods, i.e., the willingness to pay for the bundle exceeds the willingness to pay for the two separate goods. In contrast, we find no superadditivity in control treatments with only private goods. We discuss several behavioral concepts which are in line with our results as well as implications for fundraisers and firms.