Actually no, though this is a fairly standard misunderstanding of statistics. For an easy counter-example imagine generation one being [0, 100] and generation two being [1, 2]. Average wealth goes down, while every element is higher than 50% of the previous generation.
I suspect that the distribution of incomes in the US remains fairly similar to what it was 40 years ago. Thus, if the median has remained the same, then the average probably also has.
If the distribution of income had gone unchanged, the spread of wealth would also be unchanged. But it has changed, see http://inequality.org/wealth-inequality/ or the source of your choice.
If the distribution of income had gone unchanged, the percentage of the population receiving minimum wage would have gone unchanged. But it has changed, see http://www.weeklystandard.com/bls-percentage-of-hourly-worke... or the source of your choice.
I could go on... but I think that's probably sufficient. While I have you here, quick question: why did you let yourself get away with saying "I suspect" rather than just looking it up? It takes all of 10 seconds to do and once you get in the habit you'll be right way more often.
> I suspect that the distribution of incomes in the US remains fairly similar to what it was 40 years ago. Thus, if the median has remained the same, then the average probably also has.
The metric in question isn't the distribution's median. It's the percentage of children earning less than their parents.
median: sup k : { Count(xi >= k) / Length(xi) <= 0.5 }
earns more: Count(xi >= pi)/Length(xi)
These are very different values. So while I'll need to think more about the idea that medians say something about distribution similarities, thankfully those thoughts don't pertain here. For another example, of "earns more" not behaving the way you're expecting: if you set the earnings of everyone's parents to their wage - $0.01, we'd have a 0% "earns more" but extremely similar distributions.
How so? Let's say I build a popular, free, social media network. My income from the free service is zero, but the popularity has investors (which could even be average Joes pooling their money together) quite willing to buy it for millions of dollars. My wealth has now increased by millions without a respective change in income.
While I have you here: why didn't you check that before replying? (I'm actually really confused why this seems to happen constantly on HN. These are really easy things to check before posting.)
Your link does not help clear up my understanding of your premise. Perhaps it would pay to be more specific when composing your comments?