Since the beginning of the year, the Federal Aviation Administration has reported a sharp uptick in the number of passengers behaving badly.

In a typical year, the Federal Aviation Administration logs between 100 and 200 incidents. In the first three months of 2021, it reported a whopping 1300, despite the fact that the number of passengers was still well below normal levels.

It’s difficult to account for this recent uptick, but it’s hard to dispute that air rage has become a growing problem over the past few decades. The usual explanations — shrinking legroom, alcohol and flight delays — have merit. But these are arguably overshadowed by a decades-long trend: the transformation of air travel from an elite prerogative to a service that divides passengers into haves and have nots.