by Xinhua writer Guo Likun
BEIJING, Aug. 11 (Xinhua) -- From counting toothbrushes on building sites to using remote sensing satellite maps, China's officials, scholars and census takers are racking their brains to make this year's national census of the world's most populous country as accurate as possible.
About 6.5 million census takers will go door-to-door in the first 10 days of the census, which begins on Nov. 1.
Experts say increasing internal migration, greater awareness of privacy, urbanization and children born in violation of the country's "one child" policy make the census a challenging task.
DESTINATION OR SOURCE?
One of the trickiest questions is how to track China's large mobile population, which is estimated at 210 million compared with only 100 million a decade ago.
About 75 percent of the mobile population is aged 18 to 40, and about 157 million have moved from rural areas to cities for better job prospects, says Zhang Yi, a research fellow at the Chinese Academy of Social Sciences.
Almost half of the labor force in Chinese cities comes from the country's vast rural areas, says Zhang.
In addition, 30 percent of urban residents are away from their permanent residence, Zhang said.
Duan Chengrong, director of the Research Center for Population and Development under the People's University of China, says previous censuses mainly focused on the cities, or the destinations of internal migration, to count mobile population.
"But only surveying the destinations of flow increases the chance of leaving some migrant workers uncounted," Duan said. "So the government has decided to incorporate both the destinations and sources in the upcoming census to get more accurate data.
"Since residents are familiar with each other in small communities like villages, they know who went out and how many of their fellow villagers have gone to cities to work," said Duan, who is also a member of the nine-member census consultant group under the State Council.
"Generally speaking, we are trying to get an accurate head count from the sources, or the rural areas, and at the same time have an idea of their structure in the cities, such as where have they gone and what do they do in cities," he said.
Since the founding of the People's Republic in 1949, China has conducted national population censuses in 1953, 1964, 1982, 1990 and 2000.
The last census a decade ago counted 1.29533 billion people.
According to the Regulation on National Population Census, which took effect in June, China will conduct a census every 10 years from 2010.
During the last census and the trial phase of the upcoming census, local census takers have come up with practical tactics for counting appropriate for their localities.
For instance, census takers used to go to workers' dorms in construction sites or factories to count beds or toothbrushes for reference because they could not get explicit data on the number of workers from the boss, Duan said.
Wang Yanli, a census taker in Zhengzhou, capital of central China's Henan Province, took part in a trial census in the city.
"Local and permanent residents are usually more cooperative than temporary residents," Wang said. "I'm quite depressed sometimes by the temporary residents' indifference."