China's sexual revolution has resulted in a boom in the sex industry, with an estimated 20 million prostitutes in the country. Beijing-based economist Yang Fan caused a stir last year when he claimed that the sex industry now makes up a significant 12 per cent, or US$1 billion, of China's GDP, writes Miriam Donohue.

Many dispute Yang's figure, which he says he calculated by estimating prostitutes' earnings and the purchase of equipment such as expensive clothes, beepers, apartments, pharmaceuticals and even bodyguards.

Sex workers in China ply their trade at late-night barber's shops, karaoke bars, hair salons, and massage parlours, establishments that are often a front for brothels. Prostitutes also do brisk business in hotels, with many offering male guests VIP massages with extra service. Most main highways are lined with motels where truckers can find prostitutes.

The Chinese authorities launch sporadic anti-vice campaigns. The last big clampdown was 18 months ago when the authorities claimed to have shut down 50,000 karaoke bars and to have acted against 6,000 other establishments.