Comment: Remy J.-C. Pages and Dylan J. Lukes are co-equal first authors. Before collaborating, both individuals separately and contemporaneously worked on individual papers which substantially overlapped. After careful consideration all parties agreed to collaborate and produce a single unified paper. Online appendix includedUsing an additional decade of CNLSY data, this study replicated and extended Deming's (2009) evaluation of Head Start's life-cycle skill formation impacts in three ways. Extending the measurement interval for Deming's adulthood outcomes, we found no statistically significant impacts on earnings and mixed evidence of impacts on other adult outcomes. Applying Deming's sibling comparison framework to more recent birth cohorts born to CNLSY mothers revealed mostly negative Head Start impacts. Combining all cohorts shows generally null impacts on school-age and early adulthood outcomes.