How does the structure of democratic institutions affect citizen engagement? This study employs conjoint analysis to assess the effects of institutional design on political participation in participatory budgeting (PB) programs.We find evidence that PB program design strongly affects citizens' interest in participation. Participation appeals more to citizens when PB programs offer participants meaningful control over decision-making outcomes, when barriers to participation are low, and when resources allocated through PB are targeted diffusely to communities rather than individual beneficiaries. We also find that focusing PB on issues specific to marginalized communities does not necessarily boost interest in participation among members of those communities.Finally, we observe few systematic differences in preferences for participation between demographic groups traditionally associated with low rates of civic engagement compared to other groups. We then use the results surrounding PB to discuss broad implications for citizen participation in participatory institutions and democratic governance.