Zhu said metropolises attracting "gaokao immigrants" is a possibility. "But reality is reality. It's not easy at all to move to a city like Beijing," he said, citing high housing prices and living costs.

While Zhu is satisfied that most Chinese provinces issued policies to tackle the problem before the deadline, he believes metropolises could have introduced more lenient rules for long-term taxpayer families.

"It's a matter of civil rights," Zhu said.

Three patterns

According to media reports, as of a week after the deadline set by the State Council, all provinces on the Chinese mainland except Qinghai and the Tibet autonomous region announced their policies.

Yang Dongping, an education professor at the Beijing Institute of Technology who is also involved in reforming China's college entrance exam system, divides the provincial policies into three patterns.

First, more than half of the provinces, like Hebei, Heilongjiang and Fujian, set the bar relatively low for nonresident students. Candidates only need to provide a complete middle school or high school record to be eligible for entrance exams. Some provinces also require parents to provide proof of a stable job and accommodation.

These provinces, however, are traditionally hometowns for migrant workers who leave for better opportunities. In other words, the proportion of nonresidents in the population is small, Yang said.

Second, fewer than a dozen provinces, such as Shaanxi, Liaoning and Guizhou, set the bar higher for nonresident families. In these regions, not only must students have longer school records or even hukou within the next few years, their parents also have to contribute personal income taxes and social security taxes for a certain number of years before the children become eligible.

Some of these provinces, like Guizhou, although not hotspots for migrant workers, are areas where candidates benefit from low admission scores set by universities, Yang said.

Third, the toughest regions are China's metropolises of Beijing, Shanghai, and Guangdong province. Yang said in these regions the nonresident population is large. Beijing's education commission estimates that out of its 1 million schoolchildren, 40 percent are nonresident students.

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