China will conduct a national survey on China’s more than 60 million migrant children left behind by migrant workers in their hometowns. It has taken many years for the authority to finally begin mapping the full extent of social and psychological impacts on these children – and what it will do with the result remains to be seen. Like many other social issues, it only comes to the surface following entirely avoidable tragedies such as left-behind children committing suicides. But it is an indication of how serious the the issue has become over the last decade when the government told migrant parents to take children with them if they can. The problem is: very often, they cannot. Children who travel with their parents to cities, for reasons of hukou and costs, may be excluded from the well-funded public schools. The privately operated migrant schools, despite often good intentions, lack teaching and classroom resources to provide migrant children with comparable educational opportunities to their peers in public schools; and these schools are frequently demolished by the authority. There is nothing wrong with it from the point of labour and class reproduction: employers are paying workers without the need of providing education for the next generation, and both the left-behind children and those living with their parents in cities may well simply become the next generation of migrant workers ready to take blue-collar or service jobs at low wages. But it is a widely recognised social issue – with one in five children in China being affected – it is by no means a marginal issue. And if the policy goal is to increase urban population to 70-75% by 2030 in order to avoid the “middle-income trap”, the authority has to be concerned about producing a semi-permanent underclass. Allowing migrants and their children to access social services and education in cities and relaxing and eventually abolishing the hukou-based segregation system will be a necessary first step.