The best available social science shows that mandates do cause young people to stay in school, and each extra year of schooling boosts earnings by 10-14%, increases wealth by 15%, improves health, increases voting and reduces incarceration rates by 0.1% for white people and by nearly four times as much (0.37%) for Black people. In the case of compulsory schooling laws, the research lagged the policy, but there are plenty of examples of research leading policy as well. When those policies fail, the emphasis on feedback lets us know and policy change is easy because policies are changing in small steps.