At the Artistic Garden hair and beauty salon opposite where I live, the staff take a down-to-earth approach to the problem. According to the barber: "Perhaps foreigners cannot adjust to the climate, food and water in Peking. Also they don't get enough sleep and overwork themselves. So there's an imbalance in the body. Also in the winter it is windy here so it is easy for hair to drop off."
He had an interesting theory. "The hair at the back of the skull is thicker than hair at the top, especially for Chinese, because the pillows the Chinese use are harder,'' he said. "During the night the hard pillow can massage the back of your neck and head. That's why Chinese people's hair is thicker at the back. That's also why most people go bald from the front and top."
For my male colleagues with receding hairlines, the idea of trying to sleep while balanced on one's forehead on a rock-hard Chinese pillow is not that appealing. So the more desperate among them have been known to investigate the racks of hair stimulators on offer in China's stores. There is the Lily Hair Tonic produced by the Academy of Military Medical Sciences, or the Dabao (Great Treasure) Effective Hair Stimulator. But the hair-tonic sales sensation of China is the range of renowned 101 Formula products, invented by the leading "folk doctor" from Zhejiang, Dr Zhao Zhangguang, chairman of the Peking Zhangguang International Institute of Hair Regrowth and Care.
The sceptical may scoff but, proven or otherwise, 1 million bottles of 101 tonic - slogan: Glad Tidings to Alopecia Patients All Over the World - were produced last year, 40 per cent of which were exported. Mail order business is strong with the US and Japan. And despite a small bottle costing pounds 9, 101 has been tried by millions of Chinese. Above Dr Zhao's desk hangs a message of encouragement from the Prime Minister himself, Li Peng, (who suffers from a modest widow's peak despite his allegiance to 101).
At 52, Dr Zhao boasts a thick mop of black hair that somehow manages to stand upright from his head. Does he have any advice on how to keep one's hair when all around are brushing it out in sinkfuls? "Eating sesame seeds, walnuts and seaweed is good for the hair," he said. "Wash your hair once a week at most, though there are exceptions, like coal-miners. I only wash my hair every 10 days, when it starts to feel itchy, and I use 101B usually twice a month. That's the product to use before one starts going bald.''
The most recent addition to the product line is 101F (''Main ingredients: gingseng, angelica, archangelica root, wolfberry fruit, salvia officinalis, etc") which must be applied twice daily to the balding areas, leaving one smelling like some exotic liqueur. It claims an 83 per cent effectiveness rate.
101 has certainly proved effective for Mr Zhao: ''I got support from the government ... it is very easy for me to earn several hundred millions'' of yuan. Another Peking resident, Li Xiaohua, who was a sales agent for 101, was China's first Ferrari owner.
At the opposition Dabao factory, output of its Hair Stimulator is more modest at 120,000 bottles last year, 80 per cent of which was exported. Xu Yong, an engineer, said more than 30 types of Chinese herbs were included in the Dabao tonic. His own trichological epiphany came on a business trip to Brussels. ''I used French shampoo and found a lot of hair fell out. I discovered that a lot of Europeans went bald. There are two reasons. First, because Europeans eat a lot of meat, which produces a lot of fat to make the cell of the hair clog up. Secondly, some elements in the water make the hair fall out more easily. So I stopped using French shampoo and used Dabao. After one day my hair stopped falling out."
Mr Xu recommends sesame seeds and the phoenix tail fishfor warding off baldness.
What, I ventured, eyeing his bushy black hair, were the employment prospects for Dabao staff members who went bald? Of the Dabao factory's 1,200 workers, only two had gone bald, said Mr Xu. ''One is a transporter. At first the factory tried to cure him, but could not afford to continue giving him the product. So this worker bought a wig. The second one, who tests raw materials, he also wears a wig now. Because in an ordinary Chinese home it is not possible to wash every day. And this kind of product has to be used after washing hair. It takes time and money."