["Kyklos, Volume 79, Issue 2, Page 357-376, May 2026. ", "\nABSTRACT\nThis study offers causal evidence on how distinct forms of civic engagement affect government spending across 28 democracies between 2000 and 2024. Its main innovation lies in disentangling the fiscal effects of two channels of engagement—civil society participation and electoral turnout—through an original identification strategy that exploits exogenous variation in collective versus self‐interested motives. Our findings reveal that civic engagement exerts distinct effects on public spending depending on the channel through which citizens participate in democratic life. On the one hand, stronger participation in civil society associations leads to higher government spending, consistent with a publicly spirited and collective mobilisation effect. On the other hand, greater electoral participation is associated with lower public expenditure, as more collective‐interested individuals distance themselves from the traditional electoral channel, and more self‐interested individuals ask for less public spending. We explore these underlying mechanisms, propose strategies to address key identification challenges and further consider the impact of civic engagement on environmental protection and green politics dynamics.\n"]