Does Expert Input Unduly Shape Citizens’ Assemblies? Evidence from a Systematic Review of Empirical Studies

Democratic innovations such as citizens’ assemblies increasingly rely on scientific and expert input to support informed deliberation – yet this reliance also raises persistent concerns about legitimacy and elite influence. This paper synthesises evidence from a systematic review of 92 empirical studies on citizens’ assemblies and deliberative mini-publics to examine whether, how, and under what conditions expert input unduly shapes deliberation and outcomes. The review finds substantial evidence that expert input does influence citizens’ deliberations and recommendations, but that such influence is not inherently problematic. Rather, whether influence becomes undue depends decisively on institutional design and political context. Across cases, expert influence operates through identifiable mechanisms, including framing effects, authority-based deference, information asymmetries, agenda-setting, and facilitator mediation. These mechanisms are particularly pronounced in time-constrained processes, highly technical policy domains, and settings where expert selection lacks transparency or diversity. Conversely, assemblies that provide extended deliberation time, incorporate competing expert perspectives, safeguard citizen autonomy, and employ neutral facilitation consistently demonstrate participants’ capacity to critically reinterpret expert knowledge and assert independent judgment. The findings thus help reconcile seemingly contradictory assessments of citizens’ assemblies as either elite-driven or genuinely empowering. By foregrounding expert input as a central site of political contestation, this paper contributes to debates on the institutionalisation of democratic innovations under pressure. It offers evidence-based design principles to preserve legitimacy, inclusiveness, and depolarising potential – especially in contested governance environments where trust is fragile. Ultimately, the paper argues that democratic innovations can strengthen democratic repair not by excluding expertise, but by carefully governing how expertise enters deliberative spaces.