My proposal is that airlines add a new seating class to be known as Midget Class (colloquially "Sardine Class"). MC will be available only to passengers under 160cm (5ft 3 in for Americans) and 50kg(110lb). It will be priced the same as Economy and Economy will be redesignated as DeLuxe and priced at 1.4 times MC. MC seats will be smaller and stacked vertically and horizontally using a sophisticated packing algorithm. The legroom in Deluxe will be reduced by 2.5cm (one inch) from the current Economy.
BTW, between the steadily shrinking seats, nutty security theater, inability to maintain published schedules and third world chaos of airport operations, I quit flying a decade ago. I realize that not everyone has that option. But I would ask those that do, why they pay money to be subjected to modern airtravel? Buses, trains (even US trains), cars, and ships are far less aggravation. I'm far from sure that Hitchhiking isn't about as comfortable and reliable.