East / Southeast Asia's Demographic Bifurcation

There's are always interesting demographic discussions about the "West and the Rest," but there are also interesting demographic variations within regions.Take the Asia-Pacific: While Japan is emblematic of the problems with a shrinking population, it will soon be joined in that situation by a number of East Asian neighbors absent large rises in fertility or large-scale inward migration:

"Japan was largely the only country that was aging and shrinking in terms of its labor force and population in the previous decade. But in the coming decade, several Asian countries – including China, South Korea, Hong Kong [...] will see their labor forces shrink. This will have important implications for GDP [gross domestic product] growth, consumer spending and asset prices, judging from Japan's experience..."

Japan is home to the fastest aging population in the world, with almost a quarter of its population over the age of 65. The country has struggled with sluggish growth stemming from a shrinking workforce, which has put pressure on the government to boost productivity levels.

OTOH, you have the more demographically promising Southeast Asian countries that have not yet reached a similar stage in the demographic transition as their wealthier northern neighbors:

The U.N. sees the working-age population in Indonesia and the Philippines peaking in 2058 and 2085 respectively, later than previously anticipated. At the same time it brought forward forecasts for other Asian countries including China, where the working-age population is expected to peak in 2015, and its total population, currently around 1.3 billion people, is seen decreasing after 2030.

BofAML's Chua says demographics are useful indicators of real GDP growth, noting a strong correlation between changes in working-age population and growth in the real economy over the past decade (2002-2012). 

To be sure, demographics alone do not drive economic growth. However, Japan's example does illustrate the pitfalls to having too few working-age people going forward. Previously marginalized as development laggards, more are taking notice of Indonesia and the Philippines as investment opportunities partly for demographic reasons.