Policy-makers’ were unaware of how they could have increased the effectiveness of the climate policy mix

This paper is interested in the European Unions’ Fit-for-55 negotiations and to which extent policy-makers payed attention to scientific findings around instrument interactions between the EU-ETS and supplementary regulatory governance (& Perino, 2017; Gerlagh & Heijmans, 2019, Gerlagh et al. 2021, Perino, 2018, Perino et al. 2023, Willner & Perino, 2022). To what extent were policy makers aware of potential interactions and which role plays the expected impact in their decision making? We present insights from a mixed-methods approach combining a survey experiment with semi-structured expert interviews. The survey-based experiment was conducted with German policy-makers (N = 59). Participants were presented with a consequential choice between different mitigation options. Firstly, tightening of the cap in the EU ETS, secondly, a mandated reduction of emissions from coal-fired power plants, and thirdly, a combination thereof. We find that the EU-ETS tightening was the preferred option among 49% of policymakers. After the information intervention, this increased by 23%, thus in an experiment context, learning influences policymakers’ preferences to a cap tightening over a mix or regulation. With semi-structured expert interviews (26 experts on the EU level and in German politics) we illuminate the reasoning behind policy makers’ choices in the real world policy-making context. We show that contrary to the experiment, albeit being knowledgeable, this does not lead to the behaviour desirable from a model perspective, because of prior held core beliefs, moving around cleavages like trust in the market and desirable state intervention, known as motivated beliefs in the economics literature. When trying to influence the policy making process, experts need to be aware of its intricacies: every epistemic problem becomes a normative problem at some stage –policy making is not a mere adoption of scientific results, it is a negotiation between goal conflicts, where normative decisions must be made.