Well, in Canada for the most part they don't immigrate, they just buy their permanent residence status from Quebec, buy a house in Vancouver or Toronto, and then go back home.

At best they might send their wife, kids, and elderly parents over to take advantage of our subsidized schools and hospitals (for hospitals you can just borrow a fake ID from someone with PR status, Canadian culture is extremely trusting so we don't have any safeguards in place for abuse of any of our social services).