As in most professional sports, pay levels have rocketed in recent years, the more painfully as Canada's dollar has slid.

ECONOMIST: Canada

Or because Canada's dollar is strengthening (now worth 82 American cents), giving Americans a nice bump from money earned north of the border.

FORBES: Out of Energy

Because of the weakness of the Canadian dollar, clashes also loom with Canada on lumber and wheat.

ECONOMIST: Creeping protection