意図から行動へ：市民教育を通じた国境を越えた若者の選挙参加の理解

Declining youth electoral participation threatens the long-term legitimacy of representative democracy. However, timely cross-national indicators of early disengagement remain scarce. This study draws on data from the IEA International Civic and Citizenship Education Study (ICCS) to examine (a) whether eighth-grade students' stated voting intentions [are associated with] their cohort's eventual electoral participation, and (b) which individual-level factors best explain those intentions after controlling for country-level characteristics. First, we align students' voting intentions from IEA ICCS 2009 and 2016 with [corresponding] official age-specific turnout rates in each cohort's first national election. The analysis reveals a moderate, statistically significant association, indicating that higher proportions of "likely future voters" in Grade 8 are associated with higher turnout once these cohorts reach voting age. Second, to identify the drivers of voting intentions, we pool microdata from all three IEA ICCS cycles (2009, 2016, 2022; N $\approx$ 316,000 students) and estimate fixed-effects models to account for time-invariant national confounders. Results show that students' political interest emerges as the strongest predictor, followed by civic knowledge, self-efficacy, trust in the political system and its institutions, and parental political interest. Student background characteristics (e.g., gender or language at home) lose statistical significance once these factors are accounted for. The findings validate adolescent voting intentions as an early warning indicator and highlight malleable psychological levers (i.e., interest, knowledge, efficacy) that civic-education policy can target.