If penny-pinching airlines heed the advice of Norwegian Economist Bharat P. Bhatta, they’ll enact a new “pay-as-you-weigh” pricing scheme for tickets to “achieve greater efficiency, fairness and environmental stability.”

Dr. Bhatta, associate professor of economics at Sogn og Fjordane University College, called the concept “intuitive, logical and consistent with simple mathematics and economics” in a report published in the Journal of Revenue and Pricing Management this month.

The growing debate over a so-called “fat tax” began in 2008 when the rising price of jet fuel forced airlines to shift toward a model that’s dependent on ancillary revenues.

Dr. Bhatta, however, believes he has the solution to balancing the weight-fuel equilibrium.

“A reduction of 1 kilo weight of a plane will result in fuel savings worth US$3,000 a year and a reduction of CO2 emissions by the same token.”

The professor of economics cites current airline overweight policies as well as increasing fees for luggage as reasons to adopt his pay-as-you-weigh model.

“Charging according to weight and space is a universally accepted principle, not only in transportation, but also in other services,” he writes in the study. “Weight and space are far more important in aviation than other modes of transport, and airlines should take this into account when pricing their tickets.”

Dr. Bhatta suggests three possible models:

1)    Passengers pay for their flight per kilo, combining body and luggage weight for the final fare.

2)    Companies set a base fare with a per-kilo discount for “underweight” passengers and a per-kilo surcharge for “overweight” passengers.

3)    Companies set a base fare with a predetermined discount for those under a certain weight threshold and a predetermined surcharge for those above a certain weight threshold.

The professor seems to prefer the latter, noting that passengers would be free to declare their own weight. However, one in five would be selected at random and weighed to dissuade false declarations, and penalties would apply to those who attempt to cheat the system.

Many argue that such policies are not only discriminatory, but also humiliating.

“Some people consider that charging air travelers according to their body weight is not appropriate because this policy treats human beings as goods. They think that charging based on personal characteristics is discriminatory,” Dr. Bhatta notes. “Nevertheless every business does this already. This is not different but just a little hard to imagine because we are not used to weight-based fare yet.”

The CDC claims 30 percent of American adults are categorized as obese, so any policy changes would affect a large portion of fliers.

Already, the 18-inch-wide economy class seat simply isn’t possible for some obese travelers. As International Business Times noted in an earlier story on “customers of size,” current policies vary widely depending on the airline:

On Delta, passengers are not required to purchase additional seats, but they may be asked to move or wait for the next flight that has additional seating.

If you cannot demonstrate that the armrests can go down (and stay down) on a United flight, you’re required to purchase a second seat.

US Airways takes the issue on a case-by-case basis, though passengers may be required to purchase a costly second seat at the gate if they are unwilling to change flights.

Customers who are unable to fit into a single seat, unable to properly buckle their seatbelt with an extender or unable to lower both armrests must “address their seating needs” when booking on American Airlines.

Customers who may “encroach on any part of a neighboring seat” on a Southwest flight, meanwhile, should proactively book an additional seat, but they may request a refund for the cost of the additional space after travel is complete.

“Airlines have stepped up to clarify these policies over the last three or four years, and now almost every airline has a policy stated on its website,” explains George Hobica of Airfarewatchdog.com.

Whether or not they enforce the weight rules is a matter of individual perception.

“It’s up to the flight attendants and gate agents, and some people are more willing to be sympathetic,” Hobica notes. “But they don’t come out with a tape measure.”

Under Dr. Bhatta’s plan they wouldn’t come out with tape measure either. They’d come out with a scale.