Both the public and private sectors mediate economic flows across age groups. The public sector reallocates resources relying on social mandates embodied in laws and regulations and implemented by governments. Education, public pensions, and healthcare programs are important examples of public reallocations. Private sector reallocations are sometimes governed by law but are also governed by voluntary contracts, social conventions, and deeply ingrained behavior patterns that are mediated by markets, households, families, charitable organizations, and other private institutions.