While in undergrad an econ professor (who was a bit fat) convinced us that a government could tolerate any behaviour that wasn't harmful to others, in other words, that didn't generate an externality. Therefore, smoking and speed driving should be banned. But what about being fat? "Yes!" answered one classmate, "fat people use all our tax money that goes into the health system"! I also thought that they were making us unconformatble in the plane when sitting next to us. But I didn't dare to say it in front of the class, fearing I was mistaken.
Well, seems like my thought wasn't so foolish. The Economist argued for a fat tax (discussed on this blog, here and here) and now Air France is thinking of asking obese people to buy 2 tickets! (source: dailymail). Indeed, obese passengers will be charged 75% of the cost for a second seat if they are deemed too large to fit into just one . Last year United Airlines took the same decision after receiving over 700 complaints from passengers who did not have a comfortable flight due to the person next to them infringing on their seat.
This fat tax has many advantages. First, it a great way for airlines to make ends meet in these hard times. Second, it increases security, as people can now buckle up easily. And above all, it makes them pay there true environmental cost!