As national obesity levels continue to rise, Southwest employees have heard more complaints about larger passengers taking up more than their reserved seat.  For 26 out of 35 years of operation, Southwest-like other airlines-has had a policy requiring sufficiently overweight passengers to purchase two tickets; due to increasing complaints enforcement is now more common.  The definitive gauge is whether the armrest can be lowered since it's the seat boundary.  If the flight is not full then the overweight passenger qualifies for a refund. 

Discrimination complaints have been voiced by those forced to purchase extra seats but southwest maintains they cannot look the other way when an adjoining passenger has an uncomfortable or even painful flight.  Southwest also says changing plane configurations to include wider seating would cost far too much and would require huge price increases.  So far discrimination lawsuits in the US have been unsuccessful but a new government policy in Canada will cost Air Canada $7.3 million annually for the passengers considered disabled by their obesity.