Simply put, the WTA value of modern things is vastly higher than older, more tangible, more commoditized goods. I have conducted some preliminary, not-ready-for-peer-review research and discovered a huge gap differential
WTA stands for “willingness to accept,” as in how much money would you be willing to accept to have only the medical care available in 1970? As Kane points out, measuring this is very important if we are going to make well-grounded statements about how economic welfare is distributed and how it is changing over time.
Unfortunately, this research probably will not definitively answer the question of whether there were more welfare gains in 1900-1950 than in 1965-2015. We cannot go back and find the WTAs for automobiles and air travel back then.
I bet the WTA of medical care in 1970 was much higher than that of 1965, that is, before medicare.
Why?
The thing about healthcare now is it is vastly overpriced. But in the ironically named name of “access” they have put reasonable alternatives out of reach. I suspect the average WTA on many things has a modernity bias.