[0xfaded]

Given that 16% of the sample (from relocate.me) is from India, and Indians have virtually no path to PR in the US, I'm guessing residency.

Europe (at least the technocratic level) has been pro immigration for a while, so network effects probably also enter the equation.

[draklor40]

Second this. Straight forward Immigration policy. Pay taxes, take language test and in 2/3 years you get a PR. 7, for a citizenship.