If not for China 's one - child policy , world population would have hit one billion five years ago . Fertility rates in China , the world 's most populous country , are declining . That means a heavy dependency ratio . Supporters of the policy say it helped spur China 's double - digit economic growth . Policy 's unintended consequences include female unemployment , lopsided sex ratio .
If not for China 's one - child policy , world population would have hit one billion five years ago . Fertility rates in China , the world 's most populous country , are declining . Supporters of the policy say it helped spur China 's double - digit economic growth . Policy 's unintended consequences include female unemployment , lopsided sex ratio .