I think everybody agrees that it will be inferior. That was the view of my immediate successor, Munir Sheikh, and Mr. Smith just also said it won't result in comparable data. It won't result in the same quality. So we all agree that it won't.
In my mind, the main problem is not that it's going to be useless for all purposes. I think Mr. Smith is entirely right that it will be usable for a whole variety of purposes, but we won't know which ones it should be used for and which ones it shouldn't, at least not consistently, because bias is intrinsically unknowable. We can get some indications by comparing to other data and so on, but intrinsically we won't even know the response rates of the various different groups affected.
We will have an overall response rate, but we won't know what proportion of aboriginals, what proportion of low-income people, what proportion of visible minorities, and what proportion of recent immigrants did or did not respond, let alone how well the ones who responded represent the ones who didn't respond.
So there is going to be, one, a deterioration and, two, a great deal of uncertainty. While the data will be usable for a whole variety of purposes, we won't be certain for which ones they are usable and for which ones they are not.