Maybe I'll start. I'll be very short because I want Jack to have as much time as possible, since he's much more authoritative on this and most other points on economics that I am.
What's the public perception? The NDP first raised this as a major national issue, I believe, in the 1972 or 1974 campaign. Here we are, almost 50 years later, and never mind that we still don't have a good grasp on the extent of corporate subsidies and certainly don't have a good evaluation of them overall. It's easy to cite examples of where it pays off, as fellow witnesses have testified, but that has to be weighed against all the obvious failures, or the instances in which they're just subsidizing activity that would have taken place in corporations anyway.
I think overall the public sense is that this isn't a good expenditure of public dollars even if, obviously, specific actors within industry are extremely enthusiastic about it.
I'll leave the rest of the time for Jack to answer.