As the mainland prepares to hold a national census this year, demographers have been quietly revising upwards their estimates of how many people there are and how many there will be when the population is expected to peak in mid-century. The official view is that the one-child policy has been a great success, the fertility rate has fallen to 1.7 or 1.8 per cent, below replacement level, and that there are currently 1.258 billion people and by 2050 there will be 1.5 billion. It was recently reported by the Demography Research Institute of the Chinese Academy of Social Sciences, that China's fertility rate had stayed below 2.1 during the 1990s. In January, the magazine Population Science of China reported the overall fertility rate was in the 2.0 to 2.3 range. In rural China the rate was nearer 2.3 per cent, but in small towns it was around 2 and in the bigger cities just 1.2 per cent. Clearly, most couples are having at least two children and usually more. The United States Embassy's Science and Technology department recently posted on its Web site its findings that Chinese vaccine producers planned their production on the assumption that 25 per cent more children are born each year than are officially registered. Officials at the Beijing vaccine production plant which supplies northern China said they reckon 25 million children are born in China each year, not 20 million as is generally reported. In provinces such as Henan, health officials have been writing to parents asking them to have all their children inoculated whether or not they are born out of quota. One letter seen by embassy officials promised that the vaccinator would not tell the fearsome family planning officials about the extra children. As the last national census was conducted a decade ago, there are now widely differing estimates of exactly how many children have been born outside the plan and who have still not been registered. Ten years ago, demographers found there were 20 million extra people whose existence had never been suspected. Some think that at least 30 million will emerge, but as many as 100 million Chinese live in a statistical black hole. Beijing municipality for one is tightening up its one-child regulations. From April, the city said the reward for partners from one-child families who were allowed to have two children but promised to have only one would double from 1,000 yuan (HK$930). Population projections are also being adjusted. Three years ago, when Beijing hosted the World Demography Congress, officials brought forward the year when China's population would peak to 2045 and used the figure of 1.6 billion. Last December, the China Science Times reported that a prediction had been made at a meeting of the Resources and Environment Committee of the National People's Congress that the 1.6 billion population might be reached as early as 2035. By mid-century, China could therefore have 1.8 billion people, meaning that the country's population might continue to outgrow India's. Predictions that India, with a population now of one billion and a higher fertility rate of 3.3 per cent, will overtake China by the time its population stabilises in 2040 might turn out to be misguided. Twenty years ago, planners hoped that a stringent one-child policy could hold the population to within one billion by 2000 and reduce it to 700 million by 2050. Now it looks like no one can hope to control the population growth or even make a useful guess as to when it will stop growing.