NBC NEWS -- The debate over how to accommodate obese fliers on planes has long led some travelers to ask: why not just charge heavier passengers more?
Now the concept is getting support from a European economist, who argues asking fliers to pay according to their body weight is "intuitive, logical and consistent with simple mathematics and economics."
In a study published in the Journal of Revenue and Pricing Management this month, Bharat Bhatta points out it takes more fuel to transport heavier people and contends obese fliers produce more wear and tear on airline seats. So a pay-as-you-weigh system would distribute the cost of air travel more fairly among passengers, Bhatta argues.
He suggests three possible models for airlines:
Fares according to actual weight, in which carriers would set a fixed rate per pound so that a person weighing 130 pounds would pay half the airfare of a 260 pound person.
A fixed "base fare" for average weight passengers, with airlines either charging an extra fee for heavier fliers or offering a refund to skinnier ones.
Three separate fares based on whether passengers are at, below, or above average weight.
Bhatta, an associate professor in Sogn og Fjordane University College in Norway, likes the third option best.
"Sooner or later I think airlines will adopt this type of pricing," Bhatta told NBC News. But he acknowledged most people are not used to the concept and think it would be impossible to implement. His study concedes the issue is "potentially contentious because it may be viewed as discriminatory against heavier people."
Bhatta says obese fliers should be entitled to more space if they pay according to their weight and suggested airlines that adopt the pay-as-you-weigh system should install different types of seats to accommodate different size passengers.
Airline industry observers said it's not likely carriers would ever consider pricing airfare by weight.
"If I were an airline executive, I wouldn't touch this with a 30,000 foot pole," said Rick Seaney, CEO of FareCompare.com. "With the sushi menu of fees that are out there today, the camel's breaking back point is weighing people like packages as you get to the gate. This is what I would call the nuclear option at $200 a barrel oil."
Airfares change based on advance purchase, the day of the week or time of day you click the "buy" button, and how well the flight is selling, so introducing weight into the equation would just add another level of complication, Seaney said.
There would also be logistics issues to consider and privacy issues to worry about.
Still, one carrier is already charging by weight.
Calling it a world and industry first, Samoa Air -- the national carrier of Samoa -- announced the plan in December. The carrier has a fleet of small planes that are sensitive to the girth of passengers.
"Ultimately, the fairest way of charging a price is by weight," said Chris Langton, Samoa Air's chief executive, in a recent interview with Radio Australia.
"There's no doubt in my mind that this is the concept of the future because anybody who travels has traveled at times where they feel that they've been paying for half of the passenger who's sitting next to them."
More than one-third of U.S. adults are obese, according to the Centers for Disease Control and Prevention. Fliers spilling out of their seats have frustrated many travelers, so most airlines now have policies in place that address "customers of size." Many ask passengers who can't sit with the arm rests down to purchase an additional seat.