What you're probably referring to with 1973 is probably something like the increasingly lopsided share of income on the top of society. To put some exact numbers to your intuition in 1979 the middle class controlled 46% of all income, and the upper/rich classes controlled 30%. Today (as of 2014) the rich and upper class control 63% with the middle class left with 26%. [1] There's even been a chiseling out of the middle class as a whole declining from 38.8% of society to 32% of society. I also find these topics fascinating. But that paper also has another datum in it that was completely eye opening to me. This is the change in the size of each economic group as measured by share of total income from 1979 to 2014.

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- Rich: 0.1% -> 1.8%

- Upper Middle Class: 12.9% -> 29.4%

- Middle Class: 38.8% -> 32%

- Lower Middle Class: 23.9% -> 17.1%

- Poor or Near-Poor: 24.3% -> 19.8%

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That's a very positive and rapid change. As another example China is experiencing something similar on a very rapid scale. They've gone from a relatively egalitarian society, to one where you have billionaires alongside people putting together $1000 iPhones living in on-site dormitories with suicide nets lining the building, working for a couple of bucks an hour. The contrast is stark, yet at the same time their overall population is starting to benefit from unprecedented opportunity and a gradual upward push. And what's left out of that picture is that even there those workers are striving for greater things, taking that money and then using it to return to their villages and open businesses of their own hoping to get their own piece of the pie. As an extreme example there Jack Ma, now one of the richest people in the world, spent years manually biking, what would have been from his perspective, 'rich' tourists around in China from international hotels.

Maybe the biggest point about the $52k figure is how shockingly small it really is. That's with all these crazy motivations for people to earn and generate as much as they possibly can, and then some. At times it might seem that post-scarcity is just a matter of logistics and benevolence, but that's just not justified by the actual numbers. So in the mean time, rather than dream of utopia, we need to create systems that enable people with sufficient drive to get as far as they can. And while our system has an immense number of flaws, I think you'd be hard pressed to come up with a robust alternative. Social systems have a strong allure, but I think this conflict of reality and ideology is really the fundamental reason that these systems collapse, in brief order, time and again - often with extreme consequences. China's inequality may be off putting now, but it wasn't 60 years ago that Chinese were dying and starving to death by the tens of millions in their execution of a so-called 'Great Leap Forward' to a full on social system. Ultimately you need to keep perspective in mind.

[1] - https://www.urban.org/research/publication/growing-size-and-...