The relaxation of the rigid household registration system -- called hukou -- in some cities hasn't sent rural people rushing into urban areas nor would its abolition prompt them to do so, say leading labour science experts.

In fact, the number of surplus rural labourers in cities last year dropped by 28.8 per cent against 2000, even though many cities eased restrictions on employment of migrant rural labourers.

"Facts prove that a relaxation in the rules has not had a negative impact," says Chen Xiwen, deputy director of Development Research Centre under the State Council.

For, the economic factor rather than an urban residence permit is the cause of the exodus from rural to urban areas.

"Farmers are quite reasonable in their choice because they know that an urban residence permit is no guarantee of housing, employment and other social securities," Chen says.

That explains why most of the farmers have chosen to stay at home instead of leaving their farmlands for a wretched city life, without a stable income and basic living amenities, he says.

Most farmers migrating to cities take up poorly-paid, manual jobs, without the benefits their urban counterparts enjoy, such as medical care and unemployment insurance.

Mo Rong, deputy director of the Institute for Labour Studies under the Ministry of Labour and Social Security, cites nationwide figures to say that easing of hukou rules has had little impact on the influx of rural labourers into cities.

Mo's institute and the Training and Employment Department of the Ministry of Labour and Social Security have set up 1,000 offices in the country to monitor the flow of rural labourers.

"The government need not worry about an exodus of farmers," Mo says. A deeper reform of the system would not only give rural labourers a wider access to the urban job market, but also ensure an orderly flow of rural labourers into cities.

China's household registration system was introduced in 1958, according to which urban dwellers hold city residence permits and people in the countryside are registered as rural residents. It's very difficult for a person to change his residency after he's registered.

Labour science experts have been calling for a reform, for they say the system has been preventing farmers from migrating to cities freely to look for better jobs.

But authorities fear that once the system is abolished an influx of a huge number of surplus rural labourers, estimated to be about 150 million, may overburden Chinese cities.