Mainland China sent an army of six million fanning out across the world’s most populous nation on Wednesday to count how many people it has.
It will take them 10 days to collect data from 360 million households and by February the government will know how many people, how many males and females, China has.
The census will show whether the population has kept below the 1.3 billion target set for the end of 2000.
The government now reckons mainland China has 1.26 billion people while the United Nations Children’s Fund (UNICEF) says mainland China may actually have 20 million to 100 million more than that.
The amount of detail the census will provide has demographers rubbing their hands in expectation.
“It’s very important to me. For the first time we’re going to have a lot of detail about housing, size, age, space, water facilities,” said Judith Banister, a professor of demography at Hong Kong University of Science and Technology.
But census takers expect problems.
“Census workers often have to return again and again in the morning and evening to get hold of people,” said Li Tingming, a senior statistician with the Beijing city government.
“It is also difficult to persuade people to open their doors to census workers. Often they won’t cooperate and census workers really have to persuade them.”
Among the many reasons for not answering the door are children unregistered because they were born in breach of a decree barring most urban couples from having more than one.
Or the occupants may be in breach of China’s rigid registration rules, living illegally away from where they are permitted to live.
Millions of underemployed leave rural areas — where 70 percent of China’s population lives — seeking work and better lives in the cities.
By some counts there may be 200 million or more of them.
“There may be a problem with numbers. Villagers will not think (the census takers) are independent from people doing the registration,” said Siu Yat Ming, professor of sociology at the Hong Kong Baptist University.
The government has tried to temper such fears with a publicity campaign promising there will be no retributions — that all it wants are the details.
It promises not to pass on information to local governments, which run the registration system and are responsible for living conditions.
“To help ensure the accuracy of the census, the data received will not be allowed to be used to judge the achievements of local governments or various units,” the China Daily quoted an official as saying.
Census takers will interview 10 percent of the population with a detailed list of questions — right down to whether or not they have a toilet and if they do, does it flush.
The other 90 percent will have a simpler form to fill out which covers only the basics like name, age and sex.
Banister said she was also keen to see data on mainland China’s sex ratio, which has long been imbalanced with 119 boys for every 100 girls aged up to four.
“People thought the extraordinarily unbalanced sex ratios were due to selective undercounting of girls,” she said.
“But we now know, so far, the distorted sex ratios have been correct. We may discover some things have leveled out, so we are waiting for these results.”
Aborting girls accounts for a large proportion of the imbalance in a country where couples usually regard having a son as top priority, said Banister.