In 2010, the population of Asia was 4.17 billion, approximately 60% of the world's total. Asia includes not just a vast population but an enormous variety of different geographical regions and zones, countries, races, and levels of development. The demographic characteristics of its populations also vary greatly but three associated processes are found across the region, one virtually universal and the other two with different degrees of concentration. The virtually universal process is a decline in fertility, although the speed and magnitude of that decline clearly vary (Table 1). In [Page 624]East Asia, the total fertility rate—or the average number of children born to a woman by the end of her reproductive life—has declined to well below replacement level of 2.1 children and is comparable ...