China's move to raise retirement ages is a starting point to plug gaping pension deficits and bolster a shrinking workforce but more pain lies ahead as the economy slows, making further reforms urgent, say economists and demographers.

Aging populations are a global phenomenon, but the issue is particularly stark in China due to the legacy of its one-child policy, which was in place for three decades and has exacerbated its demographic challenges.

China’s number of births dropped to 9 million last year and the United Nations forecasts China's working-age population will decline by nearly 40% by 2050 from 2010 if fertility rates remain at current levels.