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!