BEIJING (BLOOMBERG) - China's population will likely peak this year, a central bank adviser said, with several provinces already reporting declines in the population growth rate.

Mr Cai Fang, a member of the People's Bank of China's monetary policy committee, said it's "entirely possible" that the world's largest population will peak in 2022, according to a report in the 21st Century Business Herald.

Separately, Yicai reported seven out of the 16 provinces that have so far disclosed birth data saw negative population growth in 2021.

With a declining labour force already acting as a constraint on the supply side of the economy, a shrinking population will become a new restriction on the demand side, Mr Cai said at a press conference late Friday (March 18).

A mismatch between demand and supply would curb economic growth, he said.

One way to boost demand is by granting migrant workers who work in the city residency permits, known as a hukou, Mr Cai said, predicting the move alone could grow total consumption by 30 per cent.

China should also take concrete measures to support household income growth, he said, in order to cope with the new demographic changes.

Mainland China had a population of 1.41 billion at the end of last year, with the growth rate rising at the slowest pace since the 1950s.

The number of babies born in China in 2021 was 10.62 million, down from 12 million in 2020, according to the National Statistics Bureau.

Populations in Jiangsu, Hubei, and Inner Mongolia provinces dropped for the first time in recent decades, according to the Yicai report. The biggest decline was in Heilongjiang, where the population fell 0.51 per cent last year, it said.

Adding to the trend, a separate Yicai report said the number of marriages in 2021 hit the lowest since records began in 1986. The 7.6 million registrations last year was 56.6 per cent of the peak reached in 2013, it said.