Designer handbag companies like Louis Vuitton and Prada have been battling against those who make counterfeit copies of their designs for decades.
But a new study suggests they should give up the fight.
A Northwestern University economist has found that sales of designer bags actually rise when sales of fake versions are also increasing.
Yi Qian disputes the theory that every fake handbag that is bought means one less handbag sold by luxury designers.
He argues that counterfeits can act as free advertisement for the real thing, boosting popularity and creating what MIT marketing professor Renee Richardson Gosline has described as a 'gateway' product.
Gosline's theory is that women who buy cheap versions, that quickly fall apart, begin to yearn for the real thing.
She found that within a couple of years, more than half of the middle-class women women she spoke to - many of who would never have considered buying an £800 bag before - actually swapped their counterfeits for authentic items.
In the early 1990s, quality-control problems among food, medicine, and oil-tank producers in China - where most fake bags are manufactured - made headlines around the world. These big stories led to the Chinese authorities cutting back their policing of fake luxury products in favour of sorting out the urgent problems with food and medicine that were making people ill.
With policing curtailed, counterfeiting took off in 1995—Qian estimates there was a nearly 100 per cent increase in the production of fakes in just two years.
Sales of mid-range bags fell over the same period but, counterintuitively, their luxury equivalents actually saw an increase in sales as people sought higher quality items.
The link between buying a fake handbag and craving an outrageously-priced real one should be worrying enough for women to avoid purchasing counterfeits altogether.
But there is another, much stronger, argument against buying cheap versions - they are often made by children in horrible sweatshops.
So if you can't afford LV, it is always best to stick to the High Street.