We document a generation gap in direct democracy outcomes across a wide range of topics that is causally related to aging. To this end, we combine different sources of postelection survey data covering more than 300 Swiss referenda and four decades. Young voters are more likely to support initiatives that favor their own generation in the present, e.g., a lower retirement age or increased unemployment benefits, or in favor of all generations in the future, e.g., environment protection. To estimate the causal effect of aging on political attitudes, we propose a novel unconstrained panel rank regression approach that separately identifies age and cohort effects. The aging effect on political attitudes is robust for controlling for arbitrary cohort effects and appears to be driven by expected utility maximization and not by habituation-induced status-quo bias.