New estimates of economic flows by age combined with population projections show that in the coming decades 1) global GDP growth could be slower by about 1 percentage point per year, declining more sharply than population growth; 2) GDP will shift towards sub-Saharan Africa more than population trends suggest; 3) living standards of working-age adults may be squeezed by high spending on children and seniors; 4) changing population age distribution will raise living standards in many lower income nations; 5) changing economic life cycles will amplify the economic effects of population aging in many higher income economies; and 6) population aging will likely push public debt, private assets, and perhaps productivity higher. Population change will have profound implications for national, regional and global economies.