German citizens misjudge the emissions reduction potential of climate policy

Do citizens know which government actions are effective in reducing carbon emissions? We present results from two studies (N = 680) suggesting that German citizens’ ability to accurately judge the effectiveness of such policies is quite limited. Moreover, judgments are systematically biased by factors that do not actually affect effectiveness. Policy endorsement, for instance, is inversely related with actual effectiveness—German citizens, on average, favor comparatively ineffective climate policy, like a ban on ultra-short distance flights, and denigrate more effective proposals, like a highway toll. However, endorsement is positively related to perceived effectiveness. This pattern aligns with the idea that a cognitive process of attribute substitution contributes to misestimations of climate policy effectiveness. Decision makers can address the complex question of policy effectiveness by answering an easier, more accessible question, like how much they endorse or could profit from introducing new regulation. Our findings suggest that citizens rely on such salient but potentially misleading cues. In consequence, they often fail to accurately assess which policies would have a bigger impact on emissions than others. The resulting judgment inaccuracy limits citizens’ ability to align their political support with sustainability intentions, highlighting the everyday consequences that a general lack of carbon competence can have for citizens.