The hukou (permanent residency permit) system, a system that restricts the free flow of the population within their own country, has caused countless heartbreaks since its adoption more than 50 years ago. It has blocked family reunions and impeded education opportunities for children and job opportunities for their parents. People without a hukou are often treated like second-class citizens in the city they have worked and paid taxes for years.

That's why when the Shanghai government on Monday announced temporary rules to reform its hukou system, it attracted nationwide attention, especially that of those who flocked to the city during the past 15 years of economic boom.

The Shanghai rules are designed mostly to attract talented professionals. Applicants must meet a minimum of five requirements - holding a local residency permit for seven years, participating in the city's social security program for seven years, paying taxes, having a mid-level professional title, and violating neither the family planning nor other laws.

Since the residency permit system in Shanghai started only in June 2002, few people meet the above five requirements. Many have questioned such stringent rules as a mission impossible for those who now work and live in the city.

However, the significance of the Shanghai reform should not be underestimated.

A small step in liberalizing the hukou system, it has sent a clear signal to all Chinese cities and governments at all levels that the long-standing and thorny hukou problem should be addressed.

Without a Shanghai hukou, people who have lived and worked in the city for years still must return to their hometowns for seemingly menial tasks, such as renewing passports, while their children are required to go back for college entrance exams. Such a system has caused immense hardships for several million Shanghai residents who don't possess a local permit. It has even deterred the many professionals Shanghai desperately needs to lure and retain.

With the new rules, professionals will find Shanghai, already a top destination for talent, an even more attractive place to make a home. This will, in return, help boost its social and economic development for many years to come.

But the new rules are not without flaws. It has excluded many people who have lived in the city for many years, working low-level jobs, such as nannies, waitresses and construction workers. They also pay taxes, abide by laws and want to make Shanghai their permanent home. But their chance of getting a local hukou seems to be slim.

One of the few immigration cities in China, Shanghai should take the lead in welcoming people from all over the country and all over the world.

The existing hukou system, which impedes free human movement and discriminates people as rural and urban, is not based on a fair and just model. It no longer suits today's society, in which hundreds of millions of people are on the move.

Reforming the hukou system is understandably no easy task, but there is no excuse for doing nothing to correct the system and ultimately abolishing it.

(China Daily February 25, 2009)