Sure.
Generally speaking, we don't do cost-benefit analyses because although the costs or the revenue streams of different measures are usually measurable, the benefits can be much more diffuse and harder to measure, in many instances. That's not to say they cannot be measured, but it's more difficult. By “more difficult”, I mean it's more subjective.
Furthermore, if we were to do a cost-benefit analysis, it would more squarely put us in the camp of being seen as determining or pronouncing on whether government policies are good or bad, which could put governments in awkward situations. Ultimately, cost-benefit analyses are the resort of legislators in your role of voting on legislation. We provide you with information on the costs, and sometimes the revenues. However, the cost-benefit analysis is better done by the government itself, I think.
With respect to alternative valuations, it's hard to criticize or comment on other people's assessments when I haven't looked at exactly how they are done. However, I know that people sometimes assess a lifespan of more than 40 years, so that increases the value of a pipeline. Given that it's very hard to figure out what oil demand will be in 40 years, going beyond 40 years is even more risky. As you go further out, there are additional revenues, but revenues in 60 or 70 years are of little added value when you're looking at an asset now.
There could be other benefits, as you and some of your colleagues have mentioned, which would increase the value of such a policy move by the Government of Canada. However, they are not relevant for a private sector buyer.