You can contact him at NERA I presume. I see him every year at Energy Modeling Forum meetings at Stanford or DC.
I am not following your story about modeling policies versus real world happenings. I, like all modelers I know, don't believe we have perfect foresight. But we critique each other based on performance over time and subjecting ourselves to rigorous critique by independent, anonymous experts - as part of the peer-review publishing process. You hane an alternative, better approach?
Statistics on carbon in fuels - and hence in emissions - is no different whether we are using carbon tax, cap-and-trade or regulations, so I fail to see your next point.
No, David's analysis is pretty close to other people modeling the California policies, both within and outside of the state. These policies in combination are having a bigger percentage reduction effect than BC's carbon tax. Of course, the issue is stringency, so this is a false discussion anyway. A more stringent carbon tax will do more than a less stringent cap-and-trade, and vice versa.
Public opinion in BC has not flipped flopped in the surveys I have seen. It was slightly positive to the carbon tax when first announced, then went slightly negative as oil prices rose in 2008, then went slightly positive again. But I note that most opinion polls are designed by people who want a certain outcome. My PhD student recently surveyed 400 British Columbians on carbon tax and other policies. What was interesting was that the carbon tax had about something like 40% of people strongly opposed. In contrast, our zero-emission electricity regulation, which stopped two coal plants and a natural gas plant that were about to be built in 2007-2008, has had a much bigger effect on emissions than the carbon tax and yet has only 1% of people were opposed to it. (More than 95% had no idea it existed.) Even without surveys like we do, astute politicians can sense this. And I think this helps explain why not a single North American jurisdiction has copied the BC carbon tax. Maybe one day. Like you, I hope so. But meanwhile, I am ready to support whatever compulsory policy we can get a politician to implement. Most likely we will get nothing. Let's not make bad odds even worse by insisting on a particular policy.