Deliberative Mini-Publics Strengthen Democratic Attitudes: Evidence from a Field Intervention with Members of the German Bundestag

Can deliberative mini-publics strengthen democratic attitudes? We study this question using a pre-registered field intervention conducted by a non-partisan NGO in collaboration with Members of the German Bundestag. Across 17 full-day events in six constituencies, randomly sampled citizens participated in structured face-to-face deliberation with elected representatives. To estimate effects, we use a placebo design comparing participants to individuals from the same districts who report they would participate if invited. Participation increases internal and external political efficacy, willingness to engage beyond voting, and political trust, with effects of 0.26-0.53 standard deviations. Participation also reduces conspiracy thinking, though this finding is less robust. Results are consistent across different identification strategies. Exploratory analyses suggest larger effects when representatives from multiple parties are present. These findings provide causal field evidence that deliberative mini-publics can strengthen key democratic attitudes and highlight their potential to reinforce democratic foundations.