Mrs Shi Wen Ying was wearing gold earrings and a cashmere cardigan when the census official arrived yesterday at her sprawling red-brick home in Long Shan village, outside Beijing. Long Shan is a model village and Mrs Shi is a model Chinese citizen, the wife of the local party secretary in fact, which was why the Beijing Population Census Office brought a couple of foreign journalists to her house to witness the start of the world's biggest census.
It is a massive national undertaking. Six million census-takers will visit 350 million households during the next 10 days to count a fifth of the world's population.
As two Pekinese dogs yelped noisily in the rose-filled courtyard, Mrs Shi told the official, Mr Thun Gang Qing, that she and her husband had two grown children, three colour televisions, and a house with 23 rooms. "What do you use 23 rooms for?" I asked. "Most are empty," she replied, explaining, "We have a tradition here of building very big houses.
If all villages were like Long Shan, China would have no difficulty counting its population accurately in the 10-day census, the first since 1990 and the most comprehensive in Chinese history - though it would get a skewed figure for average living space.
But China is a more complex country, and millions of people will spend the next few days avoiding census officials. Mr Xu, for example, whom I met in the centre of Beijing later yesterday, will not be taking part in the national count. Mr Xu is a peasant from Hunan province who makes a living selling models of locusts and frogs made from grass stalks to passers-by.
"If I see any officials coming I will run away," he said. He knew about the census from slogans in Beijing saying, "Make Faithful Declaration on Census Form" and "Population Census Benefits the Country and People", but like the small army of migrants in every Chinese city, Mr Xu is not registered and has no licence to peddle his wares. Officials to him mean only trouble.
The Chinese government has promised that the census will be secret and that officials will not report irregularities, but by the very nature of society in China, residents will identify those asking the questions with the officials who monitor their daily lives.
The result of the census, due out in February, will be eagerly awaited. The last census in 1990 recorded a population of 1.13 billion and the National Bureau of Statistics estimates that it is now around 1.28 billion. But the figure is deeply suspect.
A floating population of between 20 and 80 million people - four to 16 times the population of the island of Ireland - is believed by some demographers to be missing from national statistics.
This is because migrant workers avoid officialdom, many families refuse to register children exceeding the one-child guidelines, and officials sometimes disguise the fact that boy babies outnumber girls to an unnatural degree. If this latter trend is confirmed, it will lead to new questions about abortions and female infanticide in a country where having a baby boy is at a premium.
There are other distortions, as officials in Wuhan discovered when preparing for the census this week. They found that 8,883 residents listed as living were in fact long dead. They were workers from outside the city, still registered on the books of local factories, who had retired, returned to their home villages, and passed away.
The China Youth Daily said that in some cases companies avoided reporting the deaths so as to continue receiving their welfare benefits.
In an effort to improve the accuracy of the census, homeless people will be questioned and then given cards to keep so they are not counted for a second time. Each household will be asked about absent relatives and the local migrant population - Hong Shan village, for example, has counted 132 temporary residents from remote rural areas who live there and work in the city - to help the government to discover the size and whereabouts of the "floating population".
Mr Zhu Zhixin, deputy head of the leading group of the fifth population count in Communist China, said in Beijing that the census, which for the first time will include questions about living conditions, number of rooms and television sets, ethnicity (but not religion) and employment, will provide not only key information on China's population but also an accurate basis for the sustained development of the country in the 21st century.