Quota Adoption and Reform Over Time, or QAROT, is the first longitudinal dataset with information about the adoption, implementation, and reform of national gender quotas across the world. National gender quotas regulate (s)election to national legislatures through constitutional provisions or national laws that require some share of general election candidates or legislators to be women. The dataset includes new measures of quota design, quota thresholds, placement mandates, sanctions for non-compliance, and quota effectiveness. The authors also create a single-variable measure of the presence of an effective quota to be used by comparative politics researchers to control for this powerful institutional feature.