2. KEY FEATURES OF AGING IN ASIA
To understand the economic implications of the demographic transition, we must identify its key features, explain why it is occurring, and describe how it varies across countries. The estimates and projections presented here are based on the United Nations (UN) Population Division’s ‘World population prospects: the 2008 revision’ (UN, 2009).
2.1 The Three Phases of the Transition
Important changes in the age structure in Asia began to occur around 1950. Most populations were then young, with more than half under the age of 25. The rest were concentrated in the prime working ages of 25–59,while the percentage of the totalpopulation aged 60 and older ranged from 3 to 15 percent.
The range of age structure in 1950 is shown in the first panel in Figure 1.1. Countries are represented by bubbles that are proportional to the size of their population. The percentage of the population under