Max Duncan:

The plight of left-behind children has come to the forefront of public debate in China after several unsupervised children died in another poor region in 2015.

Some blame China's household registration system, which controls population movement by allowing people free public services like education and health care in the place where they were born, but not in the cities they move to. Authorities are reforming the system, but change has been slower in some big cities, where bringing up children is also more expensive.

Concerned about neglected children, the government is introducing more social workers to rural areas. And they are also considering tougher measures.

A new way that the authorities hope to tackle the problem is by punishing absent parents for neglecting those children. But many people are asking, until those parents are either allowed to bring their children with them or can find well-paid work closer to home, what choice do they really have?

Wang Zhenyao is a former official with China's Ministry of Civil Affairs. He supports a proposed law which would criminally charge parents who leave children without proper supervision for more than six months.