Starting in September, Wang Ming’s 12-year-old son will need to go to school in a city 120km (75 miles) from his home in Beijing. Originally from northeastern China, Wang and his wife have lived in Beijing for more than 20 years. But even though they work for a bank and an insurance company, they have never been able to obtain a hukou – the household registration document that serves as proof of residency and grants access to public services such as healthcare and education.