Strip the malls of lots of lolly, fa la la la...

With only four shopping days left until Christmas, a study has found that the UK has become a nation of consumer cheats.

More than three-quarters of shoppers have not owned up to getting too much change, 40 per cent have walked out of shops without paying for goods and 77 per cent have returned clothes after wearing them, according to a consumer survey.

Consumer theft and fraud costs UK business more than £1.8 billion a year, but Vince Mitchell of the University of Manchester Institute for Science and Technology Management School found shoppers unrepentant.

Shoppers justified dishonest behaviour by:

* Claiming stores were rich enough to bear any damage

* Denying the existence of a victim of their crimes

* Blaming the incompetence of retailers who "deserved to be cheated".

"Damaging behaviour relies on consumers' perceptions of the probability of being caught, the severity of punishment and the threat of social disapproval," Professor Mitchell said. One possible cause of the surge in retail crime - up £100 million on last year - was the significant decline in consumers' trust of businesses. At least part of the problem was a backlash against perceptions of exorbitant prices and fat-cat salaries of bosses.

"It is crucial that organisations develop a more ethical image by emphasising their moral conduct," Professor Mitchell said.

Other common activities included: buying expensive merchandise with the intention of using it before returning for a refund (23 per cent); not telling checkout assistants about missed items (38 per cent); and tasting fruit in supermarkets then not purchasing it (46 per cent).

Shoppers distinguished between active and passive unethical activity - intentional acts such as drinking the contents of a can without paying were in a different category from passive benefits such as getting too much change.

Professor Mitchell added: "Consumers are not only exploited but are also exploiters, causing tremendous loss to business. This amounts to a hidden tax on those law-abiding consumers who bear higher retail prices."