Programmers in Europe are underpaid as a group. I moved from London to New York and literally doubled my salary (almost exactly 2x). And London is at the high end for Europe.
Corollary, toilet cleaners in America are underpaid as a group. I don't want to get into a heated political debate, I just want to suggest an alternative view point that I find compelling when discussing American vs. European software salaries. Don't toilet cleaners in Germany have better lives than toiler cleaners in Kentucky?