When it comes to economic development, there is not one China but several. The rich coastal regions are the envy of those who live in the rural and much poorer interior. This has caused an unprecedented mass migration in the past two decades by people in search of jobs and a better life. But the pace of urbanisation, breathtaking though it is, cannot keep up with the population pressure. Draconian measures - based on the old permanent household registration system - or hukou - not only fail to stem the tide but make migrants more vulnerable to exploitation. The hukou, introduced in the 1950s, forces people to stay in their designated areas, outside of which they are denied essential social services and even job opportunities. Some of its harsher measures are now being reversed, especially in Guangdong, which has more migrant workers than any other province. Rudimentary pension, unemployment and industrial injury insurance have been introduced since the start of the financial crisis. These are a step in the right direction, but need to be extended much further to truly benefit Guangdong's 26 million migrant workers. Other provinces should follow its example. Now Guangdong plans to experiment with a points system by which qualified migrants can earn permanent residency. The scheme targets migrants with higher education, special skills and financial resources. It largely resembles the qualified migrant scheme used in Hong Kong to screen for applicants whose presence or skills are considered beneficial to the city. Under the Guangdong system, migrants who score high points will enjoy social services. The more points earned, the more benefits become available. For example, those who accumulate 70 points will qualify for health care not only for themselves but for their children. Eighty points will enable one's children to attend free public schools. But only those with a full 100 points will qualify for household residence. To the extent that the system, believed to be a first on the mainland, will extend social welfare to more people, it should be welcomed. But it aims to benefit only a small number of privileged migrants. Most migrant workers simply lack the special skills and resources the system looks for. Such workers have laboured for years outside their hukou and find themselves, along with their spouses and children, treated like second-class citizens. Their sweat and blood have helped build the glittering cities along the mainland's southern coast. Yet without a social safety net, they are easily exploited by unscrupulous bosses who realise they are under pressure to keep their jobs to feed themselves and their families. In major cities such as Shenzhen, up to half the working population is made up of migrant workers. Unfortunately, the hukou is likely to be retained in the near future. Like the mainland's one-child policy, it has, to an extent, helped maintain social stability and avoid widespread disruption. But its strict application is often seen by critics as a gross violation of human rights. Realistically, though, the mainland is not rich enough to enable people to move and work freely across the country. Still, this does not justify denying basic rights and services to long-time migrant workers. They deserve better for the back-breaking contributions they have made to the nation's economy. Mainland authorities need to extend the social safety net and devise a more equitable welfare system to mitigate the harsher effects of the hukou system and, eventually, to replace it.