During the 1950s and 1960s, most less developed countries were characterized by high fertility levels. Recognizing this, governments undertook sustained measures to promote family planning and provide better access to quality health services. As a result, fertility levels declined while life expectancy improved.

 

Since the turn of the century, the age structure in many less developed countries has been shifting more and more towards higher age cohorts. In South Asia, population ageing has emerged as a dominant demographic trend.