Childcare is a sector in flux. Since the 1960s, when mothers of young children first began entering the external labor force in large numbers, it has been treated largely as a market good as opposed to a social good akin to schools, libraries, and parks. After the failure of the 1971 Comprehensive Child Development Act, federal policy has considered childcare as a private good, primarily providing access as a component of the welfare system, leveraging vouchers that further marketize the sector.