Different States have different economies due to geographic locale, history, and specialization. Consequently, the US has States that specialize in agriculture, manufacturing, services, technology, natural resources, etc which have very different economics and compensation structures which is reflected in local incomes.
The median income is much higher in Washington than Mississippi, for example, but that doesn't imply anything about the distribution of income within those States. It would be like comparing incomes between the Netherlands and Romania.
Closer: San Francisco: Montgomery Street business district vs Tenderloin district
Even closer: Mission District -- Mission and 16th Street. Walk east one block and you reliable find used needles on the street. Walk west two blocks is quickly wealthy.
New York City: Manhattan vs Bronx
Closer: Upper East Side vs East Harlem (125th Street and above)
All of these pair are close and would surprise many by the huge gap in quality of life between both of them.
This one should be like catnip for HN: Palo Alto vs East Palo Alto
Are these close enough for you?
There is however a base pension that each senior citizen is entitled to. About 15% of the elderly only gets the minimal amount which in many cases doesn't cover basic expenses, like rent and food, so they need to be on social welfare as well.
But would I accept a 100% salary increase if it meant that social welfare had to be removed and people couldn't afford a place to live and to put food on the table? Of course not. Would I like if people that study hard and get well educated also get well paid jobs? Yes!
Some theories:
* High taxes actually means lower gross pay? (I am someone who strongly supports the "social safety net" -- do not read that question as some kind of weirdo libertarian / low-tax promoter.) As a counterpoint, usually high taxes means higher quality of life.
* Or: Labour mobility is higher in US than many high-tax, strong-labour countries in Europe/Japan/Korea/Taiwan. In short: It's easier to hire and and fire in US. As a result, I see massive income inequality in US, but much less in wealthy European countries -- and Japan/Korean/Taiwan.
Another way to think about it: If software engineers are paid 50% of Silicon Valley in Helsinki, then Starbucks baristas are paid 100% higher in Helsinki. (I have no hard references to offer... but my point: Lower skill jobs pay living wages in Northern Europe/Japan/Korea/Taiwan, but less in US.)
Personal question: Would you prefer to live in Sweden with your current wages, or a place with "up 100% wages for you", but much higher income inequality? When you answer, please assume much higher personal crime rates and visible poverty (or working poor).
I live in a place with simply appalling incoming inequality. The visible poverty and working poor are so depressing. I would easily take a 25% pay cut to build more social housing and help the elderly who collect cardboard to retire immediately and play with their grandchildren all day long!