The real grift is that despite the claims in that article, we all know what will really happen to the prices: standing seats will cost what economy seats used to, and every other tier bumps up.
The price per square inch of human space has probably stayed the same after inflation adjustment. People on average are just more likely to buy cheaper seats than more room, so by natural selection we get smaller seats.
Fares have come down in absolute dollar terms (let alone inflation adjusted) over the last twenty years, while economy seat sizes have barely changed.
What has changed is yield management — airlines have got much better at flying with as few empty seats as possible. So the main thing that has gone down to allow prices to decrease in real terms is your chance of getting an empty seat next to you.
Economy seat sizes haven't changed? Do you have a source for that? I'm including leg room when I say size has decreased. I honestly don't know but would be surprised, common wisdom is that leg room is much less over last 30 years.
