As to the Canadian census, I believe the main issue is that it is the only time or one of the few occasions when the disclosure process is actually mandatory. That is why the Canadian census data form the basis for many other surveys, including stratified sampling. The validity of a large number of other questionnaires, surveys and other research is based on the perceived quality of the Canadian census. This quality relies on the following two characteristics: it is comprehensive and mandatory. If we take away one of these two elements, we will face a representation problem and nothing will compensate for it. If we reduce its methodological qualities to the point of keeping only a few questions, it will be nothing more, for all practical purposes, than a count, which will not allow for the gathering of information that can support major research projects and government policies that may have positive effects.
There is a reason why big companies are conducting in-house censuses. If you do not have information about the goal or the organization you want to reach, you cannot reach it effectively. As I said in my presentation, in Canada, the mandatory five-year census is our only means of establishing a strong basis that allows us to find out who Canadians are.