That's a good question. I can't explain why it happens. I can only explain that it does happen and confirm what you're hearing as well.
We hear it regularly from our members right across the country, especially when there are short time-windows and gaps created because of excess demand for materials or for projects. It happens on a regular basis. The inability of workers to move between provinces still exists. People will say it doesn't, yet you can't actually hire the people to bring them in.
It's a real problem and it's not one sector. Nor is it the unions. It's nothing like that. It's a structural problem that we face in Canada. For some reason, we can't trust people from other provinces to be able to deal with welding a pipe together or something like that. I've even heard of examples in Alberta where the certification requires written tests so that they can't use robotic welders, which of course can't write.
It's a little bit ridiculous sometimes how tightly controlled some of these are, and it's a real challenge for industry to adapt in the face of this when we're confronting such critical labour shortages.