It takes a lot of energy to switch countries (barring something like the EU). By definition, most slackers aren't going to make the effort.

Besides that, Canada already has rules in place that deny full welfare benefits to recent immigrants.

I imagine that our current immigration policies would be sufficient to prevent this. There are probably a large number of people who would want to become citizens solely for our health care or existing safety net.

Let me be frank: It seems to be like that already for Sweden, which is a welfare state with the most open borders in EU.

That said, most immigrants to Sweden do seem interested in working -- there just seems to be a strange glut of uneducated people, compared to the available jobs.

(Remember, it is a welfare state -- high minimum wages.)

Educated people that can choose country prefer places with lower taxes -- which are high in Sweden to pay for the welfare state.

Edit: The real problem is that Sweden might be on the way to ghettos, US-style in a few decades. :-( A sociologist might mutter something about a perfect storm to generate a criminal underclass, also US-style. :-(

Edit 2: Worst case, I could go to Canada... Would love to relearn my French, anyway. :-)