This year's count is based on where people live rather than where they are registered. Over 10 days, six million census-takers will visit 400 million households to collect data about names, age and education.
The figures for migrant workers in China vary
Every day, hoards of people from the poorer provinces arrive in Beijing and China's other megacities to try their luck. Nobody exactly knows how many migrant workers there are in the country, but Duan Chengron, a migration expert at Beijing's People's University, is willing to take a guess.
"According to the official figures of 2005, there are 147 million migrant workers," he says. "But many experts say this figure is too low. I would say about 250 million. But nobody knows. That’s why we need the census."
Difficult to get hold of migrant workers
However, it is not easy to find the migrant workers and record their data. Many of them live in collective accommodation. Others share apartments where they often sleep in shifts; some even sleeping on the floor.
Parents with unregistered children might be unwilling to answer questions for the census
Feng Nailin from the National Statistics Bureau in Beijing says the over six million census-takers are likely to encounter another headache: "Citizens are far less cooperative than before and that’s a big problem. Maybe it’s because lifestyles have changed, things are much faster now and people value their private lives more."
Under Mao it was normal for the state to interfere in people’s private affairs but people are less and less willing to accept this now. During pilot runs in the summer, some census-takers were met with closed doors.
That's why Vice Premier Le Keqiang recently called on the population to cooperate: "We hope that everybody will work together so that the census information is correct and complete. Together, we will make the sixth census a great success."
The census is going to cost well over a billion dollars.
8, 18 or 45 questions to answer
During the 10-day operation, 90 percent of those questioned have to answer 18 questions – about their names, their sex, their education and their ethnic background, as well as their household registration, their "hukou", on which access to social services depends.
But 10 percent have to answer 45 questions, with more detailed information about health, living conditions, whether an apartment is rented or owned, how many rooms it has. Foreigners, who are being counted for the first time this year, have to answer only eight questions.
Many migrant workers in China live in collective accommodation
Controversial questions such as religion or income have been left out of this year’s census.
Many people are happy to take part. "I’m not worried," says one woman. "I’m not doing anything bad and I’m a good citizen. In any case, information about our income and what we own is stored at the tax office. Such information cannot be hidden. I have nothing to hide."
However, there are some who will not be so willing to answer the questionnaire – those, for example, who have unregistered children.
Author: Ruth Kirchner (act)
Editor: Arun Chowdhury