Introduction
In 1970, the first national population policy was announced in Thailand (WHO, 2003) with the primary objective to slow down a population growth rate which was higher than three percent per year (United Nations, 2011). The policy was impressively successful, leading to the decreasing fertility rate and the declining proportion of young population (aged 0-14 years old) which is regarded as dependent population. Meanwhile, Thailand was also very successful in reducing infant and child mortality, leading to the increasing proportion of youth population (aged 15 – 24 years old). As a result, Thailand experienced a youth bulge, which existed when the proportion of youth population exceeded 20 percent of the total population (Fuller. 1995 : page.151-154) during 1980 – 1990 (United Nations. 2011).
The greater youth population led to the increasing proportion of working-age population (aged 15 – 59 years old) from 50.6 percent of total population in 1970 to 66.6 percent in 2010, giving Thailand an economic benefit from the greater labor force relative to population dependent on it. Based on World Bank figures (2011), Thailand’s average growth rate of gross domestic product during 1970 – 1995 (before the economic crisis in 1997) equaled 7.78 percent per year, attributable to the increasing proportion of working-