Absolute is what matters. If 80% of your society is earning between $60k and $90k, a quintile jump around the middle is small compared to a similar shift in a $40k to $180k society. Relative mobility doesn’t buy you a vacation home.
Only from a purely acquisitive standpoint, but not with respect to social mobility which is the subject here. Also, study after study has shown that life satisfaction is more highly correlated with relative income or wealth than absolute. If we want to use science instead of personal preference to determine what matters, you're flatly wrong.
> If 80% of your society is earning between $60k and $90K
Why choose such an unrealistic example when a real one is right there? Seems suspect TBH. The real distribution is nowhere near as tightly clustered around the median, and is quite asymmetric with a much longer tail at the high end. Also, why only consider changes in the middle? A small percentile difference at either end can have a much larger effect on quality of life.
> Relative mobility doesn’t buy you a vacation home.
The difference between second and fourth quintile actually does mean something like that, and does so regardless of prices or inflation. Absolute values are the ones that become meaningless without the context of prices in a particular time and place. The house I'm sitting in right now as I write this (vs. the dumps I grew up in) is a pretty good testament to the difference between first and fifth quintile, but the price of the house doesn't matter a damn bit.
