Abstract - The world is entering a period in which the West’s postwar social welfare system is under growing threat as the global demographic structure is being turned upside down. And it is not just the West, but also China and other middle-income powers who will have to deal with an aging workforce and unsustainable health and pension costs in the next decade. For sub-Saharan African countries whose birthrates remain high, overpopulation carries big costs not only for them, but for the rest of the world, which will depend on them for a growing proportion of the world’s workforce. It is clear that managing demographic risk will be critical to every country’s future. Not making the right choices now can lessen economic potential for decades. There will be few second chances. This study examines the economic impacts of impending demographic changes.