China introduced the one-child policy in 1979 to limit couples to having only one child, as it wanted to control its rapid population growth then and improve living standards as it opened up the economy.
The policy has reportedly led to 400 million fewer births, helped in large part by draconian measures, such as forced sterilisation and abortion enforced by local governments desperate to meet official birth-control targets.
It is key in the drop in China's total fertility rate (TFR) from 2.8 in 1979 to the current 1.5 to 1.6 - below the 2.1 replacement rate - and has caused a gender imbalance, with boys outnumbering girls by 117 to 100 at birth.
But experts say the TFR would have dipped even without the one-child policy, due to rising costs of raising children, a drop in infant mortality and lifestyle changes, such as better education and job opportunities for women.
Experts also point out that birth rates have not risen even though the policy is already loosely implemented.
Before the latest exemption for couples in which one is an only child, there are existing exceptions for those from the countryside, couples who are both from single-child families, and couples from the ethnic minorities.
The subdued response to the latest policy tweak, with only one million applications to have a second child since January last year instead of the two million originally forecast, has fuelled calls for the policy to be relaxed or even scrapped.
Experts believe doing so would help tackle China's demographic challenges - ageing society and shrinking working-age population - which have exerted pressure on wages and the retirement pension scheme.
Kor Kian Beng
This article was first published on Jan 25, 2015.
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