> As for the middle class, most of the reason for the decline is people moving into the upper class.
Thats not what I get from the source you provided.
It shows that middle (and lower class) are massively losing income share:
Ine 1971, you have 88% of population in middle class or below, with 72% of total income.
81% of population remain in that bracket, but now they only get 51% of total income. That is massive, and also bad for the economy as a trend because rich people spend less of their income.
The conclusion I draw from this is that middle-class (and below) is in decline because the rich "upper-class" is soaking up much of their income.
https://en.wikipedia.org/wiki/Lump_of_labour_fallacy
More people = more economy = higher wages. Otherwise killing people and stopping other people from having children would increase your pay.
As for the middle class, most of the reason for the decline is people moving into the upper class.
https://www.pewresearch.org/race-and-ethnicity/2024/05/31/th...