It's interesting that you mention grocery stores, because although we think about consumer choice, consumers can only choose what is on offer in the grocery store shelves. Grocery stores will make decisions about what to stock or what not to stock depending on the margin they can make. If they can import subsidized European cheese at a lower cost to them than the equivalent quality Canadian cheese, they'll bring in the EU cheese and offer it to the consumer at the same price. They'll just charge whatever the market will bear. That then means that the high quality Canadian cheese will be pushed off the shelf because it's not competitive because of the subsidies the EU cheese benefits from. The consumer then doesn't even get to choose that Canadian cheese because all he or she can choose from is what's on the grocery store shelves.
On November 21st, 2013. See this statement in context.