Many good points in your post. I can’t argue that you’re wrong about this or anything else.
It’s worth keeping in mind, though, that just because something logically should happen doesn’t mean that it does happen. Sometimes good projects get unnecessarily delayed. It happens. (Maybe less often in Canada?) But when you consider a strict cost-benefit analysis, even borderline infrastructure projects are more appealing than other kinds of stimulus. If Calgary gets a new expressway that’s a bit larger than necessary, it’s not quite the problem that it would be in normal economic times. This might sound wasteful, but it’s less so than most alternatives.
Should stimulus unquestionably become necessary, other types of spending typically only provide value one time. The bombs and guns built during WWII didn’t serve a lot of good afterward. Sure, military spending triggered growth of more than 10% a year (as I said, it nearly got up to 20% for a time), but after a bomb explodes there’s nothing to show for it but a large hole in a foreign country.
In contrast, building big things serves a bigger cause than just priming the pump. Big projects also continue to be valuable afterward. Yes, there’s a risk of smaller-than-expected future returns, but smaller-than-expected returns are still more valuable than a one-time stimulus that creates no lasting value beyond the stimulus itself (which is to say, avoiding the opportunity cost of an economy that is stagnating indefinitely below its potential output level).
As for the time frame: we’ve already had a year of recession in the US, with the situation getting worse and worse. For a normal recession, the window would in all likelihood be too short to matter, but we are most probably looking at the long haul here, an extended worldwide slump. Maybe Canada will avoid the worst of it. I really hope you do. But you might be looking at a situation where you got plenty of warning to prepare for big projects.
Of course, I can’t be 100% certain about that. It might indeed be worth waiting and choosing a stimulus policy only after you’re absolutely sure you’ll need it, which would mean doing without the long term benefits of a well timed project. There are reasonable arguments on both sides.* I’m not trying to tell you all what to do, I’m just saying that this stuff is worth thinking about. Projects can be fast-tracked, delay can be reduced. If there is any potential construction that would add real value in the long term, but which you’d be hesitant about in normal times for whatever reason, now is the time to seriously consider getting the process started.
*Ignoring the misinformation that’s continually spread about previous economic crises.