Jakob Kilian Bilan, Robert Birkmayer, Ewa Jarosz, Etienne Oriot and Clara Simões Coelho – a team of students from Sciences Po – took part at the first EIB Climate Survey hackathon. The team has explored the social dimension of climate finance in their research titled Determinants of altruistic willingness-to-pay for an environmental tax. Focusing on Germany, Sweden and Italy, the study investigates what motivates individuals to support climate policies that benefit those with lower incomes. Using data from the EIB Climate Survey and Eurostat, the team finds that climate concern and trust in government are key drivers of support, while older age groups show less willingness to contribute. Their findings offer valuable insights for designing fair and effective climate taxation.
Could you summarise the focus of your research? What was the main question your team set out to answer?
Our study examined what motivates people to be willing to pay an extra tax specifically to finance climate policies that benefit people with lower incomes than themselves. This ‘altruistic WTP’ focuses on the social dimension of cost distribution, using data from Germany, Sweden, and Italy to see if factors like concern, trust, and age drive this willingness to redistribute resources.
Could you tell us which non-EIB datasets you used, and which questions from the EIB Climate Survey were most important for your findings?
External Databases: To account for local economic context, we integrated regional income inequality data (S80/S20 ratio at the NUTS 2 level) from Eurostat into our country-level analyses.
EIB Survey questions: Our focus was on EIB Q20, 2024: "How much extra tax on your yearly income would you be willing to pay to finance climate policies that benefit people with lower income than yourself?". This ordinal variable, ranging from 'Nothing' to '10% of your yearly income', was the core of our study. Our predictors were other questions from the same survey, covering both socio-demographic and attitudinal factors. For instance, we used the percentage of correct answers to the knowledge questions to measure Climate Knowledge, and Q1, 2024 to identify climate concern.
If you had just 30 seconds to speak to a decision-maker or journalist, what key insights about public support for climate action would you want them to understand?
1. Climate concern is the single most powerful driver of WTP: The strongest predictor across all three countries is how worried someone is about climate change. For highly concerned respondents in Germany, for example, the odds of accepting a higher tax rate increased by 149%.
2. Trust in government is critical for accepting new taxes: People are far more likely to accept the new tax if they trust their government to implement effective climate policies.
3. A gap in intergenerational support: Individuals in older age groups (specifically those 50 and over) are consistently and significantly less likely to support paying higher tax rates for climate benefits compared to younger generations.