Lee, RonaldMason, AndrewAmporfu, EugeniaAn, Chong-BumBixby, LRBravo, JorgeBucheli, MarisaChen, QiulinComelatto, PabloCoy, DeidraRice, James2015-12-101095-9203http://hdl.handle.net/1885/63374Longer lives and fertility far below the replacement level of 2.1 births per woman are leading to rapid population aging in many countries. Many observers are concerned that aging will adversely affect public finances and standards of living. Analysis of201410.1126/science.12505422015-12-10