DUBAI // Consumers are losing tens of millions of dirhams each year when they are not given the correct change at the checkout, according to economic and finance experts.
The practice of rounding off totals is essential to maintaining efficiency in the system, they say - but what we lose on one day is balanced off with gains when stores round down on others.
Anecdotal evidence suggests about Dh30 million may slip through consumers' fingers every year, though experts stress a scientific study has yet to be carried out.
Although high, the figure is far below that quoted in recent media reports, which suggested up to Dh100m could be lost every year.
"To say it is between Dh50m and Dh100m is to assume that figures are always being rounded up, which isn't the case," said Dr Steven Buigut, the head of accounting, finance and economics at the American University in Dubai's school of business administration.
"What you will find is that shops will round down just as much but, as a consumer, you will tend to remember the times when things are rounded up."
Dr Buigut said the answer was not to mint more coins through the Central Bank - because the cost of doing so is often more than the coin's face value.
"It is expensive to mint extra coins and bring them into circulation. To mint a penny, for example, would cost you about 1.3 pence because the base metal is more expensive," he said of the smallest element of UK currency. Any savings, therefore, would be swallowed up by the minting process, Dr Buigut said.
"In my own experience, I've had some days where the figures seemed to be rounded up and others when they were rounded down," he said.
"Even if you say 60 per cent of shops will round up, that still leaves a hefty total that will more likely round down. The trouble is, it's impossible to say for sure if people are losing out because, in most cases, it's anecdotal."
Professor Tarek Coury, an economist at the Dubai School of Government agreed, saying reader surveys were notoriously inaccurate, with only those motivated enough to respond giving their views, while the vast majority of the public stay silent.
"I think it's a bit of a red herring, to be honest," he said. "There is a selection bias in these kinds of surveys and, unfortunately, no scientific study has been done. Much of the figures being bandied about are through anecdotal experience.
"Even if you are being overcharged 50 fils once a week, that adds up to Dh2 a month."
The only way to be sure of always paying the correct amount is to pay by credit or debit card, Prof Coury said. "In most cases this is how people do pay for items anyway, as it's not practical to carry around so much cash. I would also advise consumers to do bulk buying whenever possible.
"The thing to keep in mind is that not everywhere accepts payment by card - and the places that do not [take cards] tend to have cheaper products, because they do not have the overheads associated with a card-payment system.
"So although you might not be getting the exact change back, the products you buy will be cheaper."
For shoppers it is an annoyance, but something they grudgingly accept. "I guess sometimes I have been undercharged and sometimes overcharged," said Vicky Andrews, a British expatriate housewife who lives in the Springs area of Dubai.