Airlines should consider a new pricing policy - ‘pay as you weigh' - which would take into account not just the weight of passengers' baggage, but the passengers themselves, an international economist has said.

According to Dr Bharat Bhatta of Sogn og Fjordane University College in Norway, such a policy could benefit passengers and airlines.

He set out to investigate the economic justification for airlines charging prices according to a passenger's weight. This included assessing the idea of rewarding passengers who manage to reduce their weight or who weigh less than average.

"Charging according to weight and space is a universally accepted principle, not only in transportation, but also in other services. As weight and space are far more important in aviation than other modes of transport, airlines should take this into account when pricing their tickets," Dr Bhatta said.

He pointed out that heavier passengers make a plane weigh more, which in turn requires more expensive jet fuel. Increased fuel can also be damaging to the environment.

As a result, charging passengers according to their weight could promote better health, as well as leading to environmental and financial savings for the airline.

Dr Bhatta suggested three workable models:

-Fare dependent on actual weight - this means charging a person for how much they and their baggage weigh. There could be a fixed rate per kg so that, for example, a person weighing 50kg pays half as much as a person weighing 100kg

-A base fare plus or minus an extra charge - this would see a fixed base rate being charged, with heavier passengers paying an extra charge. With this option, every passenger could end up paying a different price

-Average weight passengers paying the same fare, with a lower/higher fare for lower /higher weight above or below a certain limit - this model leads to three different price types, low, average and high.

Dr Bhatta said that he believes the third option would be the best. He also emphasised that any ‘pay as you weigh' policy that charges heavier passengers more, but does not charge lighter passengers less, ‘only benefits the airlines'.

Details of Dr Bhatta's research are published in the Journal of Revenue and Pricing Management. Commenting on the findings, the journal's editor, Dr Ian Yeoman, noted that ‘every extra kilogram means more expensive jet fuel must be burned, which leads to CO2 emissions and financial cost'.

"As the airline industry is fraught with financial difficulties, marginally profitable and has seen exponential growth in the last decade, maybe they should be looking to introduce scales at the check-in," he commented.