This book is a quantitative assessment of the challenges China faces as it tries to achieve the twin goals of mitigating the effects of population aging while containing the overall size of the population. After a close examination of the impact of China's fertility policies on the country's population structure and size, the author presents empirical evidence for the effectiveness of finely calibrated easing of the country's decades-long birth control policies for both of these objectives. This research uses an innovative quantitative indicator-the Aging and Economic Coordination Index (AECI)-to measure the macroeconomic pressure population aging places on the country. This is the first time the AECI has been systematically applied to gauge the magnitude and the trends of that pressure for the 1980-2050 period, and to provide the basis for policy suggestions about what might be done to ease that pressure.