Deliberative, Representative, or Both? How Institutionalising Minipublics in Policymaking Shapes Political Attitudes

Deliberative mini-publics are widely argued to improve the perceived legitimacy of policymaking. Yet, we know little about how their effects on the wider public compare with other forms of advice that policymakers routinely use. This paper reports findings from a pre-registered factorial survey experiment (n = 2,376) that benchmarks citizens’ assemblies against five other sources of advice (experts, public meetings, written consultations, polling, and interest groups) and across 42 separate policy issues. Citizens’ assemblies raise perceived legitimacy compared to a process that sought no external advice, but they fall in the middle of the ranking. Experts and consultations produce larger gains, and only polling lowers legitimacy. Emphasising an assembly’s deliberative features, its representative features, or both makes no noticeable difference. Instead, where the advice is used is more important than the kind of advice. Any advisory input raises the legitimacy of a parliamentary process, but adds nothing to referendums, which are rated more legitimate at baseline. Advice also raises legitimacy most among policy losers, though without increasing their acceptance of the outcome. Overall, citizens’ assemblies strengthen perceptions of legitimacy but as one credible source of non-binding advice among several.