Mean. Median has remained more or less flat.
Trend is clearly up, although some generations can experience a flat decade or so. Comparisons with 'back in the days' (e.g. 70s) show a clear 50% or so increase.
While for one 1975 dollar you would need to invest 5.22 today's dollars because of inflation [1].
So today the median income has massively less buying power compared to 1975 while chained dollars still outgrew the inflation.
Not yet sure what to make of this, but it might not be the success story.
[1]: https://www.in2013dollars.com/us/inflation/1975#:~:text=Why%....
Wait, I don't follow. What I linked was real median income, i.e. it's already adjusted for inflation. So median income in fact has >58% more purchasing power than 1975.
This is nominal personal income: https://fred.stlouisfed.org/series/MEPAINUSA646N
It grew by a factor 6.7x, whilst prices (using your inflation link) grew by a factor 5.23, since 1975. That translates to a purchasing power improvement of 28%. Different from the 58% figure above (which may use different inflation benchmarks), but obviously an improvement of purchasing power nonetheless.
If you compare that to slightly fewer working hours (5-6% reduction) and slightly more leisure (a few extra holidays), longer life expectancy (72->79) and longer retirements (5 -> 10y average), I'd say an improving purchasing power despite this is definitely a success story!
In my experience taking one single metric (be it mean or median) without context is more often than not because it supports a specific politicsl/ideological point of view.
Using the mean in this case supports the notion that globalization was a win for the American society.
Using the mean alone shows that it more or less did nothing (but maybe also did not hurt).
Showing the distribution or the mean increase per income bracket would show it benefitting the upper income/net worth levels while maybe hurting the people on the lower end.
Comparing income with buying power for specific goods (like done in other places of this discussion) is also often dependent on the political/ideological point of view.
Others have stated that nowadays everybody has a supercomputer in their pocket (implying things got better through globalization) while others pointed out that the average worker cannot afford a home for themselves and their family (implying globalization wasn't so great - at least not for everyone).
So it takes context and different metrics to at least paint a rich picture to enable us to rationally discuss good and bad sides of a phenomenon like globalization and what could be done to fix the bad things (if we (not you and me, but all discussion participants) could find middle ground in defining the same things as being bad).
I've yet to hear any of the former group actually say that they'd rather live on the street with an iPhone than in a house they owned in the 1960s with a rotary in spite of that being the implication.
Agreed that people cherry pick the specific goods vs inflation to defend their point of view. TVs vs College are typical examples of radically cheaper vs radically more expensive.
The housing situation is quite a bit more nuanced though, in my opinion. A lot of data shows it hasn't really been getting more expensive.
For one, we're not comparing the same houses. The average home size in 1969 was 1200 square feet. Today it's over 2400 square feet, or double.
Second, we're not comparing the same members of the household. Homes were shared by 3.33, now by 2.5. That's in part an indication of cultural change, but also in part a change in wealth and luxury, as the number of single-person households more than tripled since 1969, something unaffordable at the time.
Then there's the costs of the loan. Virtually nobody, certainly not first-time buyers, outright buys a home in cash, not then and not now. Homes are financed with mortgaged. The price of a mortgage is in the interest rate. Paying off the principal isn't an expense because it reduces your liability, any debt paid off means the equity is now yours, and if you sell the home you get the cash back. The interest you never get back, it's the price of the loan. The interest rate was 7.5%, now it's 3.5%, less than half.
Putting it all together, yes, nominal home prices are about 15x higher today. But the cost to rent money to own a certain size home per person, is indeed 14.8 / (3.332.55) (1200/2500) / (7.5*3.55) = 2.57x as expensive, nominally. Whilst median personal income grew by about 6-7x [0]
In other words, housing has gotten cheaper. It's the reason current prices are sustained despite the average house being 2x as big, and shared by 25% fewer people. The reason housing prices are so high is because we're living in bigger homes and sharing them with fewer people and paying less on the financing costs.
Not only 1.5 times like the median income: https://news.ycombinator.com/item?id=30325835