Winners and losers

On Wednesday, Beijing and Shanghai, two of China's biggest cities, announced new rules on car-hailing services that will ban drivers without local hukou, also known as household registration, from working in the sector.

The move hasn't been universally popular: when the local governments put the proposals out for public consultation, 25 percent of respondents said unregistered residents should be allowed to work in the industry.

However, as super-sized conurbations with serious cases of "big city disease" - severe air pollution and a lack of housing and public services - Beijing and Shanghai have already set targets for population control and the upgrading of their industrial structures.