International climate adaptation assistance: Assessing public support in Switzerland

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 17 / 26 PLOS ONE Support for adaptation assistance in Switzerland Geographic regions and country perception The results of our baseline model in Fig 2 (which pools respondents across control and treatment groups) reveal notable differences in the favorability of climate aid and climate migration policy packages across recipient countries. Swiss respondents tend to favor policy packages for the Philippines, while they tend to disfavor policy packages for Algeria. We find indifference towards Bangladesh and Kenya. Stronger positive favorability for Bangladesh policy packages and in some instances for Kenya policy packages becomes evident in conditional effects models, which we discuss later. Results for Hypothesis 5 are thus mixed. For reference, in the Japan study, Uji et al. [26] find partial support that the public favors climate adaptation assistance to neighboring Asian countries. Specifically, they found that Japanese respondents support policy packages to Bangla- desh (but not to Cambodia) in relation to Tanzania (Africa) or Peru (Latin America). What might account for such variation among Swiss respondents in policy package favora- bility across recipient countries? As previously hypothesized, some respondents might associate the geographical location of countries with the likelihood of increased migration. For example, migrants from a geographically closer country may face lower costs of moving to Europe and

may have access to more informal routes to reach a country such as Switzerland. Consistent with Hypothesis 5, we do find that Algeria – the country closest geographically to Switzerland – as the recipient country has a significant negative effect on policy favorability. Although the Algerian community in itself is not very strongly present in Switzerland (4,152 Algerian nationals, [92]), the total number of foreign citizens from the Maghreb (i.e., Tunisia, Morocco, and Algeria) is quite significant for Switzerland (around 20,000 individuals, [92]). Hence, historical immigration inflows, coupled with the proximity of Algeria to Switzerland, could partially explain this result. Furthermore, in the European context, immigration, particularly from Africa and the Mid- dle East, has become a politically salient issue. Media stories about boat crossings from North Africa are a regular feature in the news cycle, which can shape public views in this respect [93]. Studies conducted in West European countries have further suggested that immigrants from North Africa became subject to security- and cultural-threat frames in European media [71]. Moreover, France is a former colonial power in North Africa, which has shaped both migration patterns but also prejudice vis-à-vis migrants. These factors could influence per- ceptions about migration from countries such as Algeria, given the extensive land borders and linguistic connection between France and Switzerland. The favorability of policy packages containing immigration in host countries is sometimes

influenced by the perceived demographic characteristics of immigrants, such as gender, linguistic fluency, and skill level [94]. Swiss citizens potentially associate immigrants from specific countries with certain types of demographic characteristics, and this influences their favorability for overseas climate policies. At the same time, we find that Swiss respondents are indifferent regarding Kenya – also an African country and more proximate to Switzerland compared to Bangladesh and the Philippines. This could be because immigration from Kenya specifically is neither salient nor politically instrumentalized. The Kenyan community in Switzerland is quite small, with 1,853 citizens residing in Switzerland in 2022 [92], and these factors might explain the overall indif- ference of the respondents. Similarly, the South and Southeast Asia region might not be directly associated in the public mind with waves of migration as they do not receive much media attention. Moreover, unlike North Africa, the substantial distance from Asia implies a lower likelihood of climate migrants seeking shelter in Switzerland. Thus, reference to these countries does not diminish the favorability of climate policy packages. Yet, our results are mixed in this regard, as respon- dents are indifferent to Bangladesh but prefer policies aimed at the Philippines. The consistent

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 18 / 26 PLOS ONE Support for adaptation assistance in Switzerland preference for the Philippines thus deserves additional exploration. Filipino residents in Switzerland do not constitute a large community (6,423 individuals, [92]). Still, similarly to Algerians, they are more present than Bangladeshi and Kenyan citizens (around 1,704 and 1,853 respectively, [92]). Whether Swiss residents hold particularly positive social represen- tations of the Filipino community, and whether this explains our results, however, should be researched further. Because of the multiple factors encompassed by geographical location and the absence of a direct test of the proposed mechanisms that would allow for disentangling them, additional studies are needed to understand what specific features of the recipient country drive citizens’ favourability of policy packages. Interestingly, however, our results suggest that the identity of the recipient country influences policy favorability only in specific subsets of the sample (Supporting information S8 Fig, S9 Table, S10 Fig, S11 Table, S12 Fig, S13 Table). Indeed, the significant positive effect for the Philippines and the negative effect of Algeria disappears amongst young respondents (18–34 years old), amongst highly educated ones, and respondents with medium to high incomes. In other words, the results are insignificant for each of the four recipient countries in these sample sub-groups. This may imply that racial and cultural preju-

dices are lower among the younger generation and demographics with higher education and income (Supporting information S4 Fig, S5 Table, S6 Fig, S7 Table, S8 Fig, S9 Table). At the same time, however, the position of respondents on the political spectrum (Support- ing information S23 Fig, S24 Table), their beliefs about integration (Supporting Information S12 Fig, S13 Table), and their pride towards Switzerland do not significantly alter our main results in this respect (Supporting Information S14 Fig, S15 Table). Benchmarking and support for adaptation assistance Recall that the conjoint experiment is nested within a framing experiment. Might the respon- dents’ favorability of aid or immigration be conditioned by benchmarking with other OECD countries (Treatment 1), or with Switzerland’s existing policies (Treatment 2)? After all, the general public may not have deep knowledge about actual aid and immigration levels within Switzerland or in its peer countries. Thus, providing context might reduce the knowledge gap and shape the policy preferences of respondents. We find no significant differences across treatment groups. In further analysis, the interaction of aid and immigration with treatment dummies does not produce statistically significant results (Supporting Information S16 Fig). This is broadly consistent with Uji et al. [26] which reports that benchmarking with respect to past Japanese policy and peer G7 countries did not produce statistically significant effects. Conditional effects of political ideology and cultural beliefs

Finally, to further explore the robustness of the main findings of our experiment, we also explored the conditional effect of political ideology and cultural beliefs as factors likely to influence the favorability of policy packages, given the highly contentious immigration and climate policy debates. Studies of climate politics in Switzerland note the consistent divide between right-wing and left-wing coalitions on climate policies [72–74,95]. Research on pub- lic opinion and foreign aid has similarly emphasized the variation across the left-right political ideology spectrum [23,24,46]. While conservatives tend to oppose migration, we do not find political ideology to condition the favorability of policy packages either for the aid or immi- gration dimensions of the policy package (Supporting Information S23 Fig, S24 Table). Finally, we examine how individual beliefs might condition preferences for policy pack- ages, even after controlling for ideology. Consider the interaction effects of cultural views based on consideration of language affinities (Supporting Information S10 Fig, S11 Table),

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 19 / 26 PLOS ONE Support for adaptation assistance in Switzerland cultural affinities (Supporting Information S12 Fig, S13 Table), and expressions of pride for Swiss history and culture with the baseline model (Supporting Information S14 Fig, S15 Table). All these factors are important in the contemporary discussion on populism. Much to our surprise, these interaction effects did not influence results in a statistically significant manner. Divergent views on the utility of development aid as a policy instrument (or lack thereof) similarly did not significantly affect our results. Conclusion This paper makes several contributions to the study of climate politics. We join the growing movement that links climate policy to broader policy debates on immigration, foreign aid, and trade. Substantively, this study provides important insights into how Swiss respondents view the subject of climate aid and immigration in the context of specific developing countries. It reveals that the favorability for policy packages that substantially increase climate adaptation aid correlates positively and consistently with recipient countries’ trade volumes and voting alignment with the Swiss position in international forums such as the UN Security Council. Respondents consider such issue linkages in expressing their favorability for adaptation assis- tance. The favorability of policy packages with climate adaptation aid and accepting migrants

increases as countries trade more with Switzerland and vote alongside the Swiss position in the UN Security Council. High levels of trade and alignment of votes in the UN Security Council with Switzerland increase the favorability of policy packages with ambitious aid levels and some level of climate migrant acceptance. While Switzerland maintains its neutrality in global politics, it is notable that public respondents (as opposed to policy elites according to standard expectations of the literature) regard countries that vote alongside Switzerland at the UN Security Council as more desirable partners for climate adaptation assistance. These results resonate with theories on development aid and issue linkage to gain traction on other international priorities. They furthermore suggest that establishing linkages with other issues (such as trade) and international regimes (such as international security and potentially other domains) could strengthen awareness domestically and public opinion in favor of increasing climate adaptation assistance. To our knowledge, the politics of linking adaptation finance with other international issues, such as trade and UN-level cooperation, has not been previously explored in the literature. Comparable findings in the case of Japan for UN General Assembly vote alignment and countries receiving Japanese exports [26] fur- ther imply broader generalizability of the relevance of such issue linkage for directing climate adaptation assistance beyond the Swiss context. Such political dynamics and their implication

can be explored with a broader comparative perspective, including for traditionally large donors such as the United States and countries in the European Union. Another significant result is the evidence of diminished support for the assistance pack- age that is directed to Algeria, while positive support is provided for packages directed to the Philippines. This suggests that the political and media representation and rhetoric aimed at North African countries might be influencing the perceptions of Swiss respondents. We are reluctant to frame this as purely religion-based discrimination bias because Swiss respondents do not reveal these negative preferences towards Bangladesh, another country with a similar background in terms of the prevalence of the Muslim religion, but with different geographic proximity and colonial past linked to continental European. Equally, despite cultural similar- ities between the Philippines and Kenya in terms of large shares of predominantly Christian population, we found support for the Philippines but a lack of support for Kenya, except for models with conditional effects of trade and UN voting. Thus, future research should explore the multidimensionality of factors that might guide public support for climate-induced migra- tion and how this coheres with other drivers of migration, such as war and economic distress.

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 20 / 26 PLOS ONE Support for adaptation assistance in Switzerland In the context of Switzerland, as in other industrialized countries, climate mitigation has dominated climate change politics. To the extent that adaptation is discussed [95,96], it is in the context of vulnerabilities at the domestic level, exemplified in the case of Switzerland by concerns about mountainous regions and vulnerable sectors, or concerning most vulnerable sections of society. Climate policy proposals have thus focused primarily on mitigation objec- tives under the overarching international treaties including the UNFCCC, the Kyoto Protocol, and the Paris Agreement [97]. Our study suggests that as a consequence of the traditional focus and contestation of climate mitigation, questions of adaptation aid and finance have fallen on the sidelines of public attention at best, as indicated by the insignificant results in the absence of linkage to trade and alignment of Security Council votes. These findings are important, as they are likely indicative of a broader tendency of low pub- lic attention to international adaptation aid in industrialized countries. This raises questions about what kind of international platforms and domestic policies are needed to both increase the salience of adaptation aid and foster productive issue linkage for its ratcheting up. From a justice perspective, however, issue linkage could provide a double-edged response. Projecting

a strategic view of climate adaptation aid and international trade, security, and other strategic priorities of donor countries may increase the public support for, and volume of, adaptation finance. Yet, this might not be necessarily good news for climate justice, as the direction of aid is more likely to carry the imprint of the economic and foreign policy interests of donors. The issue linkage perspective thus raises questions for further research on what kinds of linkage ought to be fostered across international regimes and norms of justice, equity, and humanitari- anism, as means of amplifying the domestic resonance of adaptation aid policies. Finally, while we focus on adaptation, we recognize that some effects of climate change (such as desertification, salination, or the loss of land to sea level rise) are particularly hard to adapt to [98]. Hence, the 2015 Paris Agreement officially recognized (Article 8) that the subject of Loss and Damage needs to be addressed separately from adaptation. Future work could explore whether the emergence of Loss and Damage as an issue in its own right might strengthen or crowd-out support for climate adaptation. Supporting information S1 File. Survey. (PDF) S2 Fig. Descriptive statistics. (PDF) S3 Table. Baseline estimates. (PDF) S4 Fig. Interaction with age. (PDF) S5 Table. Interaction with age. (PDF) S6 Fig. Interaction with education. (PDF) S7 Table. Interaction with education. (PDF) S8 Fig. Interaction with income. (PDF)

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 21 / 26 PLOS ONE Support for adaptation assistance in Switzerland S9 Table. Interaction with income. (PDF) S10 Fig. Interaction with immigrant language. (PDF) S11 Table. Interaction with immigrant language. (PDF) S12 Fig. Interaction with culture. (PDF) S13 Table. Interaction with culture. (PDF) S14 Fig. Interaction with Swiss pride. (PDF) S15 Table. Interaction with Swiss pride. (PDF) S16 Fig. Interaction with the experimental benchmarking. (PDF) S17 Table. Interaction the with experimental benchmarking. (PDF) S18 Table. Interaction with Swiss trade. (PDF) S19 Table. Interaction with UN Security Council votes. (PDF) S20 Fig. Average Marginal Interaction Effect (AMIE). (PDF) S21 Table. Fifty treatment combinations with the highest treatment effect. (PDF) S22 Table. Fifty treatment combinations with the lowest treatment effect. (PDF) S23 Fig. Interaction with the left-right political spectrum. (PDF) S24 Table. Interaction with the left-right political spectrum. (PDF) Acknowledgments We are grateful to Isabelle Stadelmann, Karin Ingold, Vally Koubi, Stefano Jud, Quynh Nguyen, Tim Büthe, Sungmin Rho, and Lena Shaffer for feedback at different stages of this project. Author contributions Conceptualization: Liliana Andonova, Agnese Zucca, Nives Dolšak, Aseem Prakash. Data curation: Agnese Zucca, Simon Montfort. Formal analysis: Simon Montfort.

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 22 / 26 PLOS ONE Support for adaptation assistance in Switzerland Funding acquisition: Liliana Andonova, Nives Dolšak. Investigation: Liliana Andonova, Agnese Zucca, Simon Montfort, Nives Dolšak, Aseem Prakash. Methodology: Liliana Andonova, Agnese Zucca, Simon Montfort, Nives Dolšak, Aseem Prakash. Project administration: Liliana Andonova, Agnese Zucca. Resources: Liliana Andonova, Agnese Zucca. Software: Agnese Zucca, Simon Montfort. Supervision: Liliana Andonova. Validation: Liliana Andonova, Agnese Zucca, Simon Montfort, Nives Dolšak, Aseem Prakash. Visualization: Simon Montfort. Writing – original draft: Liliana Andonova. Writing – review & editing: Liliana Andonova, Agnese Zucca, Simon Montfort, Nives Dolšak, Aseem Prakash. References 1. Putnam RD. Diplomacy and domestic politics: the logic of two-level games. Int Org. 1988;42(3):427–60. 2. Newell P, Mulvaney D. The political economy of the ‘just transition’. Geogr J. 2013;179(2):132–40. 3. Aklin M, Mildenberger M. Prisoners of the wrong dilemma: why distributive conflict, not collective action, characterizes the politics of climate change. Glob Environ Polit. 2020;20(4):4–27. https://doi. org/10.1162/glep_a_00578 4. Dolšak N, Prakash A. Three faces of climate justice. Annu Rev Polit Sci. 2022;25(1):283–301. https:// doi.org/10.1146/annurev-polisci-051120-125514 5. Gaikwad N, Genovese F, Tingley D. Creating climate coalitions: mass preferences for compensating

vulnerability in the world’s two largest democracies. Am Polit Sci Rev. 2022;116(4):1165–83. https:// doi.org/10.1017/s0003055422000223 6. Andonova LB, Hale TN, Roger CB. National policy and transnational governance of climate change: substitutes or complements? Int Stud Q. 2017;61(2):253–68. https://doi.org/10.1093/isq/sqx014 7. Andonova LB, Hale TN, Roger C, editors. The comparative politics of transnational climate gover- nance. Routledge; 2018. 8. Brink E, Wamsler C. Citizen engagement in climate adaptation surveyed: the role of values, worldviews, gender and place. J Clean Prod. 2019;209:1342–53. https://doi.org/10.1016/j. jclepro.2018.10.164 9. Harris BS, Howe PD. What factors are associated with public support for climate change adaptation policy in the U.S.? Environ Res Commun. 2023;5(9):091003. https://doi.org/10.1088/2515-7620/ acf4e1 10. Yazar M, York A. Disentangling justice as recognition through public support for local climate adaptation policies: insights from the Southwest US. Urban Climate. 2022;41:101079. https://doi. org/10.1016/j.uclim.2021.101079 11. Ray A, Hughes L, Konisky DM, Kaylor C. Extreme weather exposure and support for climate change adaptation. Glob Environ Chang. 2017;46:104–13. https://doi.org/10.1016/j.gloenvcha.2017.07.002 12. Kruse T, Atkinson G. Understanding public support for international climate adaptation pay- ments: evidence from a choice experiment. Ecol Econ. 2022;194:107321. https://doi.org/10.1016/j. ecolecon.2021.107321

13. Klöck C, Molenaers N, Weiler F. Responsibility, capacity, greenness or vulnerability? What explains the levels of climate aid provided by bilateral donors? Environ Polit. 2018;27(5):892–916. https://doi. org/10.1080/09644016.2018.1480273 14. Donner SD, Kandlikar M, Webber S. Measuring and tracking the flow of climate change adaptation aid to the developing world. Environ Res Lett. 2016;11(5):054006. https://doi. org/10.1088/1748-9326/11/5/054006

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 23 / 26 PLOS ONE Support for adaptation assistance in Switzerland 15. Biermann F, Boas I. Preparing for a warmer world: towards a global governance system to protect climate refugees. Glob Environ Polit. 2010;10(1):60–88. https://doi.org/10.1162/glep.2010.10.1.60 16. Surminski S, Oramas-Dorta D. Flood insurance schemes and climate adaptation in developing coun- tries. Int J Disaster Risk Reduct. 2014;7:154–64. https://doi.org/10.1016/j.ijdrr.2013.10.005 17. Pielke R Jr, Prins G, Rayner S, Sarewitz D. Climate change 2007: lifting the taboo on adaptation. Nature. 2007;445(7128):597–8. https://doi.org/10.1038/445597a PMID: 17287795 18. Ciplet D, Roberts JT, Khan M. The politics of international climate adaptation funding: justice and divi- sions in the greenhouse. Glob Environ Polit. 2013;13(1):49–68. https://doi.org/10.1162/GLEP_a_00153 PMID: 27019649 19. Sengupta S. Climate change, international justice and global order. Int Aff. 2023;99(1):121–40. https:// doi.org/10.1093/ia/iiac264 20. Dolšak N, Prakash A. The politics of climate change adaptation. Annu Rev Environ Resour. 2018;43(1):317–41. https://doi.org/10.1146/annurev-environ-102017-025739 21. Roberts JT, Weikmans R, Robinson S, Ciplet D, Khan M, Falzon D. Rebooting a failed promise of climate finance. Nat Clim Chang. 2021;11(3):180–2. https://doi.org/10.1038/s41558-021-00990-2 22. Weikmans R, Roberts JT. The international climate finance accounting muddle: is there hope on the

horizon? Clim Dev. 2017;11(2):97–111. https://doi.org/10.1080/17565529.2017.1410087 23. Lumsdaine DH. Moral vision in international politics: The foreign aid regime, 1949-1989. Princeton University Press; 1993. 24. Milner HV, Tingley D. Public opinion and foreign aid: a review essay. Int Interact. 2013;39(3):389–401. https://doi.org/10.1080/03050629.2013.784090 25. Gampfer R, Bernauer T, Kachi A. Obtaining public support for North-South climate funding: evidence from conjoint experiments in donor countries. Glob Environ Chang. 2014;29:118–26. https://doi. org/10.1016/j.gloenvcha.2014.08.006 26. Uji A, Song J, Dolšak N, Prakash A. Public support for climate adaptation aid and migrants: a conjoint experiment in Japan. Environ Res Lett. 2021;16(12):124073. https://doi.org/10.1088/1748-9326/ ac3b7b 27. Skenderović D. Immigration and the radical right in Switzerland: ideology, discourse and opportunities. Patterns Prejudice. 2007;41(2):155–76. 28. Ruedin D, D’Amato G. The politicisation of immigration in Switzerland: the importance of direct democ- racy. In: Van der Brug W, D’Amato G, Berkhout J, Ruedin D, editors. The politicisation of migration. London: Routledge; 2015. p. 140–58. 29. Hutter S, Kriesi H. Politicising immigration in times of crisis. J Ethnic Migra Stud. 2021;48(2):341–65. https://doi.org/10.1080/1369183x.2020.1853902 30. Engberg-Pedersen L, Vammen I, Lucht H. Can European foreign aid motivate people to stay in Africa? Dev Policy Rev. 2024;42:e12761. 31. Todaro MP. A model of labor migration and urban unemployment in less developed countries. Am

Econ Rev. 1969;59:138–48. 32. Clemens M. The emigration life cycle: how development shapes emigration from poor countries. IZA Discussion Papers, No. 13614. Bonn: Institute of Labor Economics (IZA); 2020. Available from: https:// docs.iza.org/dp8592.pdf 33. Koubi V, Spilker G, Schaffer L, Bernauer T. Environmental stressors and migration: evidence from Vietnam. World Dev. 2016;79:197–210. https://doi.org/10.1016/j.worlddev.2015.11.016 34. Spilker G, Nguyen Q, Koubi V, Böhmelt T. Attitudes of urban residents towards environmen- tal migration in Kenya and Vietnam. Nat Clim Chang. 2020;10(7):622–7. https://doi.org/10.1038/ s41558-020-0805-1 35. Kelley CP, Mohtadi S, Cane MA, Seager R, Kushnir Y. Climate change in the fertile crescent and implications of the recent Syrian drought. Proc Natl Acad Sci. 2015;112(11):3241–6. https://doi. org/10.1073/pnas.1421533112 PMID: 25733898 36. Alesina A, Dollar D. Who gives foreign aid to whom and why?. J Econ Growth. 2000;5(1):33–63. 37. Lundsgaarde E, Breunig C, Prakash A. Instrumental philanthropy: trade and the allocation of foreign aid. Can J Pol Sci. 2010;43(3):733–61. https://doi.org/10.1017/s0008423910000661 38. Milner HV, Tingley D. The choice for multilateralism: foreign aid and American foreign policy. Rev Int Organ. 2012;8(3):313–41. https://doi.org/10.1007/s11558-012-9153-x 39. Hicks RL, Parks BC, Timmons RJ, Tierney MJ. Greening aid? Understanding the environmental impact of development assistance. Oxford University Press; 2008.

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 24 / 26 PLOS ONE Support for adaptation assistance in Switzerland 40. Halimanjaya A, Papyrakis E. Donor characteristics and the allocation of aid to climate mitigation finance. Clim Change Econ. 2015;06(03):1550014. https://doi.org/10.1142/s2010007815500141 41. Bauhr M, Charron N, Nasiritousi N. Does corruption cause aid fatigue? public opinion and the aid- corruption paradox. Int Stud Q. 2013;57(3):568–79. https://doi.org/10.1111/isqu.12025 42. von Hermanni H, Neumann R. ‘Refugees welcome?’ The interplay between perceived threats and general concerns on the acceptance of refugees – a factorial survey approach in Germany. J Ethnic Migr Stud. 2018;45(3):349–74. https://doi.org/10.1080/1369183x.2018.1459183 43. Ghosn F, Braithwaite A, Chu TS. Violence, displacement, contact, and attitudes toward hosting refu- gees. J Peace Res. 2018;56(1):118–33. https://doi.org/10.1177/0022343318804581 44. Abdelaaty L, Steele LG. Explaining attitudes toward refugees and immigrants in Europe. Polit Stud. 2020;70(1):110–30. https://doi.org/10.1177/0032321720950217 45. Rich TS, Bison K, Kozovic A. Who is welcome? South Korean public opinion on North Koreans and other refugees. Jpn J Polit Sci. 2021;22(3):117–29. https://doi.org/10.1017/s1468109921000116 46. Bansak K, Hainmueller J, Hangartner D. Europeans’ support for refugees of varying background is stable over time. Nature. 2023;1–6. 47. Draper J. Labor migration and climate change adaptation. Am Polit Sci Rev. 2021;116(3):1012–24.

https://doi.org/10.1017/s0003055421001313 48. Helbling M. Attitudes towards climate change migrants. Climatic Change. 2020;160(1):89–102. https:// doi.org/10.1007/s10584-020-02697-3 49. Castellano R, Dolšak N, Prakash A. Willingness to help climate migrants: a survey experiment in the Korail slum of Dhaka, Bangladesh. PLoS One. 2021;16(4):e0249315. https://doi.org/10.1371/journal. pone.0249315 PMID: 33886603 50. Gamso J, Yuldashev F. Does rural development aid reduce international migration? World Dev. 2018;110:268–82. https://doi.org/10.1016/j.worlddev.2018.05.035 51. De Haas H. Turning the tide? Why development will not stop migration. Dev Chang. 2007;38(5):819– 41. https://doi.org/10.1111/j.1467-7660.2007.00435.x 52. Berthélemy J-C, Beuran M, Maurel M. Aid and migration: substitutes or complements? World Dev. 2009;37(10):1589–99. https://doi.org/10.1016/j.worlddev.2009.02.002 53. Clemens MA. Does development reduce migration? Lucas RE, editors. International handbook on migration and economic development. Edward Elgar; 2014. p. 152. 54. Runfola DM, Napier A. Migration, climate, and international aid: examining evidence of satellite, aid, and micro-census data. Migr Dev. 2016;5(2):275–92. https://doi.org/10.1080/21632324.2015.1022969 55. Berlin MP, Desai RM, Olofsgård A. Trading favors? UN Security Council membership and sub- national favoritism in aid recipients. Rev Int Organ. 2022;18(2):237–58. https://doi.org/10.1007/ s11558-022-09467-z 56. Kiratli OS. On the question of generosity: who supports foreign aid to whom?—lessons from Turkey

and Greece. Int J Public Opin Res. 2019;32(1):176–88. https://doi.org/10.1093/ijpor/edz008 57. Doherty D, Bryan AC, Hanania D, Pajor M. The public’s foreign aid priorities: evidence from a conjoint experiment. Am Polit Res. 2020;48(5):635–48. https://doi.org/10.1177/1532673x20939925 58. Heinrich T, Kobayashi Y. How do people evaluate foreign aid to ‘nasty’ regimes? Brit J Polit Sci. 2018;50(1):103–27. https://doi.org/10.1017/s0007123417000503 59. Dreher A, Sturm J-E, Vreeland JR. Global horse trading: IMF loans for votes in the United Nations Security Council. European Econ Rev. 2009;53(7):742–57. https://doi.org/10.1016/j. euroecorev.2009.03.002 60. Kuziemko I, Werker E. How much is a seat on the security council worth? Foreign aid and bribery at the United Nations. J Polit Econ. 2006;114(5):905–30. https://doi.org/10.1086/507155 61. Miller AR, Dolšak N. Issue linkages in international environmental policy: the International Whal- ing Commission and Japanese Development Aid. Glob Environ Polit. 2007;7(1):69–96. https://doi. org/10.1162/glep.2007.7.1.69 62. Tingley D, Tomz M. International commitments and domestic opinion: the effect of the Paris Agree- ment on public support for policies to address climate change. Environ Polit. 2019;29(7):1135–56. https://doi.org/10.1080/09644016.2019.1705056 63. Burkhalter D. What to expect when Switzerland heads UN Security Council? SwissInfo. ch. [cited 2023 Apr 28]. Available from: https://www.swissinfo.ch/eng/politics/ what-to-expect-when-switzerland-heads-un-security-council/48471784

64. De Graffenried V. Le jour où la Suisse Entra au Conseil de Sécurité. Le Temps. [cited 2022 Jun 9]. Available from: https://www.letemps.ch/suisse/jour-suisse-entra-conseil-securite

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 25 / 26 PLOS ONE Support for adaptation assistance in Switzerland 65. Dolšak N, Dunn M. Investments in global warming mitigation: the case of “activities implemented jointly”. Policy Sci. 2006;39(3):233–48. https://doi.org/10.1007/s11077-006-9020-9 66. Hafner-Burton EM, Mosley L, Galantucci R. Protecting workers abroad and industries at home: rights- based conditionality in trade preference programs. J Conflict Resolut. 2018;63(5):1253–82. https://doi. org/10.1177/0022002718783236 67. Bayramoglu B, Jacques J-F, Nedoncelle C, Neumann-Noel L. International climate aid and trade. J Environ Econ Manag. 2023;117:102748. https://doi.org/10.1016/j.jeem.2022.102748 68. Haas PM, Keohane RO, Levy MA, editors. Institutions for the earth: Sources of effective international environmental protection. MIT Press; 1993. 69. Tingley D, Tomz M. Conditional cooperation and climate change. Comp Polit Stud. 2013;47(3):344–68. https://doi.org/10.1177/0010414013509571 70. Bayram AB, Holmes M. Feeling their pain: affective empathy and public preferences for foreign devel- opment aid. Eur J Int Relat. 2019;26(3):820–50. https://doi.org/10.1177/1354066119890915 71. Eberl J-M, Meltzer CE, Heidenreich T, Herrero B, Theorin N, Lind F, et al. The European media dis- course on immigration and its effects: a literature review. Ann Int Commun Assoc. 2018;42(3):207–23. https://doi.org/10.1080/23808985.2018.1497452 72. Ingold K. Network structures within policy processes: coalitions, power, and brokerage in Swiss

Pub Pol. 2021;42(1):136–64. https://doi.org/10.1017/s0143814x21000088 80. Hainmueller J, Hangartner D, Yamamoto T. Validating vignette and conjoint survey experiments against real-world behavior. Proc Natl Acad Sci. 2015;112(8):2395–400. https://doi.org/10.1073/ pnas.1416587112 PMID: 25646415 81. Bansak K, Hainmueller J, Hopkins DJ, Yamamoto T. The number of choice tasks and survey satisfic- ing in conjoint experiments. Polit Anal. 2018;26(1):112–9. https://doi.org/10.1017/pan.2017.40 82. Boas TC, Christenson DP, Glick DM. Recruiting large online samples in the United States and India: Facebook, Mechanical Turk, and Qualtrics. Polit Sci Res Methods. 2018;8(2):232–50. https://doi. org/10.1017/psrm.2018.28 83. Zack ES, Kennedy J, Long JS. Can nonprobability samples be used for social science research? A cautionary tale. Surv Res Methods. 2019;13(2):215–27. 84. Mullinix KJ, Leeper TJ, Druckman JN, Freese J. The generalizability of survey experiments. J Exp Polit Sci. 2015;2(2):109–38. https://doi.org/10.1017/xps.2015.19 85. Horiuchi Y, Markovich Z, Yamamoto T. Does conjoint analysis mitigate social desirability bias? Polit Anal. 2021;30(4):535–49. https://doi.org/10.1017/pan.2021.30 86. Hainmueller J, Hopkins DJ, Yamamoto T. Causal inference in conjoint analysis: understanding multidimensional choices via stated preference experiments. Polit Anal. 2014;22(1):1–30. https://doi. org/10.1093/pan/mpt024 87. Leeper TJ, Hobolt SB, Tilley J. Measuring subgroup preferences in conjoint experiments. Polit Anal. 2019;28(2):207–21. https://doi.org/10.1017/pan.2019.30

88. Brönnimann S, Appenzeller C, Croci‐Maspoli M, Fuhrer J, Grosjean M, Hohmann R, et al. Climate change in Switzerland: a review of physical, institutional, and political aspects. WIREs Clim Chang. 2014;5(4):461–81. https://doi.org/10.1002/wcc.280

PLOS ONE | https://doi.org/10.1371/journal.pone.0317344 February 12, 2025 26 / 26 PLOS ONE Support for adaptation assistance in Switzerland 89. OECD. Development co-operation profiles. OECD Publishing, 2023. 90. SWI. Switzerland to fund new projects along migration route in Africa. [cited 2022 Mar 30]. Available from: https://www.swissinfo.ch/eng/politics/ switzerland-to-fund-new-projects-along-migration-route-in-africa/47476546. 91. Egami N, Imai K. Causal interaction in factorial experiments: application to conjoint analysis. J Am Stat Assoc. 2018;114(526):529–40. https://doi.org/10.1080/01621459.2018.1476246 92. Federal Statistical Office. Bilan démographique selon la nationalité. 2022. Available from: https://www. pxweb.bfs.admin.ch/pxweb/fr/px-x-0103010000_151/px-x-0103010000_151/px-x-0103010000_151.px/. 93. Genovese F. Empathy, geography and immigration: political framing of sea migrant arrivals in Euro- pean media. Eur Union Polit. 2023;24(4):771–84. https://doi.org/10.1177/14651165231180758 94. Denney S, Green C. Who should be admitted? Conjoint analysis of South Korean attitudes toward immigrants. Ethnicities. 2020;21(1):120–45. https://doi.org/10.1177/1468796820916609 95. Javeline D. The most important topic political scientists are not studying: adapting to climate change. Persp Pol. 2014;12(2):420–34. https://doi.org/10.1017/s1537592714000784 96. Hadden J, Prakash A. Introduction: What scholars know (and need to know) about the politics of climate change. Polit Sci Polit. 2024;57(1):17–20. https://doi.org/10.1017/s1049096523000562

97. Kammerer M, Ingold K. Actors and issues in climate change policy: the maturation of a policy dis- course in the national and international context. Soc Netw. 2023;75:65–77. https://doi.org/10.1016/j. socnet.2021.08.005 98. McNamara KE, Bronen R, Fernando N, Klepp S. The complex decision-making of climate-induced relocation: adaptation and loss and damage. Clim Policy. 2016;18(1):111–7. https://doi.org/10.1080/146 93062.2016.1248886