Sebastian H. Schneider examines, using individual and aggregate data, which individual and contextual factors influence citizens' participation in municipal budget planning (participatory budgeting). The author contributes to foundational research in political science, as such consultative-dialogic participation processes are expected to become more widespread. Additionally, the study provides insights for municipal political practice by uncovering causal relationships, thereby enhancing understanding of the success and failure of such processes, even though a mechanical control of participation is neither possible nor desirable.