The wage in US is high but the expenses there follow the same path. You pay for health, school, insurance (a lot of them), etc. The rent are crazy and the food runs on the same way. In Europe, these services are free (or almost free), even in small countries. Also, the rent is less expensive.
This is a huge difference on the end of the month. What I pay for an apartment on the center of Amsterdam is a dream to people on SF bay and Valley but my wage is very close of some fellows there.
This is just a point to consider with the numbers.