Samoa Air charges by the pound

Some airlines are beginning to charge obese customers for extra seats, but Samoa Air appears to be the first to adopt a "pay as you weigh" pricing plan.

The airline's price-per-kilogram will vary depending on the flight, from as little as $1 per kilogram to as much as $4.16, reports the Sydney Morning Herald.

In a radio interview this week, according to the paper, Samoa Air chief executive Chris Langton defended the new policy. "This is the fairest way of traveling," Langton said. "There are no extra fees in terms of excess baggage or anything—it is just a kilo is a kilo is a kilo."

Passengers now must type in their weight and the weight of their baggage into the online booking section of the airline's website.

"When you get into the Pacific, standard weight is substantially higher," Langton continued. "That's a health issue in some areas."

He said the new policy is intended, in part, to raise awareness of Samoa's weight problem.

The Pacific island nation has one of the most obese populations in the world. According to a 2007 World Health Organization survey, more than 80 percent of Samoans age 15 and older are considered obese, making it the sixth fattest nation in the world. Nauru, in the South Pacific, topped the list, with 94.5 percent of its 9,322 inhabitants obese.

(Photo Samoa Air)

Samoa Air operates a fleet of small BN2A Islander and Cessna 172 planes, some with as few as eight seats.

"Airlines don't run on seats, they run on weight, and particularly the smaller the aircraft you are in, the less variance you can accept in terms of the difference in weight between passengers," Langton said. "Anyone who travels at times has felt they have been paying for half of the passenger next to them."

He may be right. According to a 2010 survey conducted by Skyscanner.net, 76 percent of travelers said airlines should charge overweight passengers more if they needed an extra seat.

Last month in the Journal of Revenue and Pricing Management, Bharat Bhatta, a Norwegian economist, recommended that airlines adopt a "pay as you weigh" program.

"To the degree that passengers lose weight and therefore reduce fares, the savings that result are net benefits to the passengers," Bhatta wrote.

(Dylan Stableford - Yahoo News)