Now I come across a graph that makes it plain:
I suppose much the same happened here in the UK. So that's why we got all those posh-cooking and property-in -Provence TV programmes. We were encouraged to dream about the top echelon, not try to join them. As Eva Peron said, "I am taking the jewels from the oligarchs for you"; but somehow we never got to wear them ourselves. Not unless we went into hock for them.
This Wiki entry on the Gini coefficient remarks "Overall, there is a clear negative correlation between Gini coefficient and GDP per capita; although the U.S.A, Hong Kong and Singapore are all rich and have high Gini coefficients." Perhaps there is going to be a reversion to the standard international model: a poorer USA with a high Gini coefficient. Or (same source) a reversion to the social stratification of 1929:
1929: 45.0 (estimated)
1947: 37.6 (estimated)
1967: 39.7 (first year reported)
1968: 38.6 (lowest index reported)
This blog projects a Gini convergence between the USA and Mexico - perhaps it makes sense, on the reversion-to-mean basis: