These days, many people in Guangzhou registered under group residence permits issued by the human resources market center are reluctant to get married. They would lose their residence permits if they tie the knot.

China's residence permit, or hukou, system dates back to ancient times but has grown increasingly troublesome as people become more mobile. Hukous are usually issued per family, listing the births, deaths, marriages and address of every member.

In the case of singles who move to cities like Guangzhou for work and don't own homes in the city, employers usually provide them with a group residence permit, putting all the employees into one hukou under a single address – usually the employer’s administrative office.

In Guangzhou, some residents are also able to register their hukou under the local government employment agency's address. The agency does not allow married workers to get a group residence permit. Thus, if a person with a group residence permit wants to marry and remain in Guangzhou, he has to first own a house in the city so that he could register for a hukou with the address. Rising housing prices have made that option next to impossible for many people.

So many young people choose not to get married. A person with the username PSYG recently posted his troubles on Bulletin Board System, an online forum. He had bought a house in the neighboring and less expensive city, Foshan, thinking about marriage. But he also knew he would lose his Guangzhou residence permit if he moved to Foshan.

"After considering the issue over and over, I gave up the idea to get married," he wrote.

While there is no law forbidding people with group residence permits in Guangzhou to marry, officials at the residence permit administrative office say that allowing them to do so would cause many difficulties. Among them, because the hukou is administered per household and family, it would hinder enforcement of the one-child policy.

"It's hard for us to follow those registered under group residence permits [issued by the employment agency] to see if they are abiding by the one-child policy," said Liu Jun, a human resources officer at Southern Human Resources.

Some experts think the policy prevents a flexible talent pool from forming. "On one hand, we encourage the talents to move freely," said Tan Jianguang, a professor at Guangdong Youth Cadres Management College. "On the other hand, the old residence permit system curbs their movement and dampens their creativity."

The policy has led to the creation of a market where group residence permits issued by the employment agency can be shared among friends and relatives for 3,000 yuan to 5,000 yuan.