That's a good point, and it comes up often.
My office has a mandate to estimate the cost and impact of certain measures. In general, the government is very good at talking about the benefits of its proposals. Where there is often an information asymmetry is when we talk about the costs or repercussions of certain measures. If I were doing cost-benefit analyses, as is sometimes suggested, my office should have a mandate that is considerably different from its current mandate.
Furthermore, it would be difficult to estimate the benefits of a measure such as the capital gains inclusion rate, because it would then have to be determined where the funds would be paid. The government said it would use the funds for certain purposes, but it could have generated revenue in other ways. If we did cost-benefit analyses, it would force us to become policy analysts and to comment on the merits of certain very specific policies.
That is why we only estimate the costs of certain measures. We leave it to parliamentarians to arbitrate and determine the ratio between costs and benefits. For our part, we provide the information on the costs. The government, on the other hand, often provides very good information on the benefits. By putting all that together, legislators—in this case you and your colleagues—are able to make good trade-offs and arrive at good decisions.