How were people encouraged to have only one child in China?

· whenThe policy was introduced in 1978 and initially applied to first-born children in the year of 1979. · whyIt was created by the Chinese government to alleviate social, economic, and environmental problems in China and authorities claim that the policy has prevented between 250 and 300 million births from its implementation until 2000 and 400 million births from 1979 to 2010.