frozentripper wrote:
IMHO (i really don't shop much) avoiding American buying is going to be difficult with the likes of megamonster American-owned multinationals like ..., McDonald's...
You might want to take a deeper look at McDonald's Canada's supply chain, franchise ownership and where the revenue ends up. I think their advertising of using 100% Canadian beef goes back to at least the early 1980's if not the 70's. They haven't made as much noise about other ingredients, but I expect they have a very high percentage of Canadian content overall. Add to that the fact that many franchises are locally owned and operated, hire local residents as employees including a high percentage of students and a boycott of a local McDonald's could be having exactly the opposite effect of what you desire. McDonald's Canada also has a further degree of separation from the McDonald's U.S. company at the corporate level which is not necessarily the case in other parts of the world.
On the building materials side, I'm not sure there are many alternatives in large urban centres. Rona is now ownede by Lowes but may still stock a larger number of Canadian produced parts. Timb-r Mart appears to still be wholly Canadian owned although their stock will not be entirely Canadian produced.
Preferentially buying Canadian isn't a bad thing and I thing when it comes to food, particularly fresh fruit, vegetables, meat, dairy, etc. that it is extremely worthwhile. The risk of a broad buy Canadian campaign is that there are enough layers involved that it often isn't clear just how much or little Canadian "content" there is in a particular product.
Ontario is particularly vulnerable due to the extreme lengths the province has gone to in order not to develop trade with the rest of Canada. Oil is one part of that, but the Transcanada highway to the west was severed a year and a half ago by a single bridge failure (January 10, 2016). A single lane of alternating east-west traffic was reopened the next morning.
That's right - Canada was linked east to west by a 1-lane bridge in 2016! It took a month and a half to get back to providing a single lane each direction and as far as I can tell a permanent repair has still not been completed. I would far rather be eating range fed Alberta beef than the imported US grown beef we get in supermarkets in southern Ontario but the trade network simply doesn't exist to support it.