All the talk of addressing the global imbalances throws a spotlight on contrasting demographic trends in the world’s two most populous nations — China and India.

Prior to the financial crisis, India’s annual growth rate of about 9 percent seemed positively moribund next to China’s double-digit economic expansion. But purely on demographics, the dimming power of the US consumer could give India an edge over its neighbour in the longer run.

That’s what India’s trade minister Anand Sharma seemed to suggest last week when he reminded the audience at a London conference that the country had “20 percent of the world’s children”:

We know that when we talk about emerging countries the consumption patterns are different. Most of China’s production is meant for (markets) abroad. India consumes two-thirds of what India produces.

Indeed, Goldman Sachs projects that India’s middle class will outstrip China’s by 2045. This is some 15 years after half of China’s population becomes either too old or too young to be part of the workforce.

Beijing’s mandarins are taking note of this monumental shift in dependency ratios. After decades of enforcing a ‘one-child’ policy in the face of an human rights outcry, China appears to be relaxing its stance on population control. Family-planning officials in Shanghai have begun to urge eligible couples to have two children.

BlackRock Asian equities portfolio manager Jing Ning says it’s useful for investors to start thinking about this demographic shift. Healthcare providers, for instance, will look increasingly attractive investments.

“For the next 20 years, it will be critical for the government to reform its social welfare system,” she said.