There have been times when Mexico was desperately short of people, e.g. 1560 (after all the plagues), the early 1700s, late 1800s, and so forth.
Sometimes the Mexican economy (and living/working conditions) has outperformed that of the North American British colonies.
Depends on what part of history you look at. At the moment Mexico is not as well off as the US. This may change.
Oh, yes, and historically speaking, Latin America has been a primary target for Spanish emigration. Today, Spain is a target for immigration ~ much to the relief of the folks who live there. Spain is actually looking to Latin America as a source for new workers (who are culturally, religiously and linguistically compatible).
All in all it's better to live in a place folks want to get into than to live in one where they want to leave.
Spain would be better off with Mexican and Latin immigrants than muslims.
Glad to hear this - have been thinking for years how much better off all of Europe would have been if they had encouraged Mexican immigrants instead of muzzies.
Western, nominally Christian, pick up many of the European languages easily.