The NCB report is equally based on a lot of assumptions. They assume that life expectancy will continue to rise, they assume that fertility will remain at current levels. Interestingly, after 2020 they expect immigration to fall to 0.
The problem, as I see it, is that the predictions, as such, will stand or fall on those assumptions. In other words, the report is in a nice pdf, but it is still speculation per se. I suppose that makes it no different to the property market in itself.
What interests me is the general short termist view of looking at things here. Property doesn't crash overnight. It might crash over seven or eight months, and the cracks might be visible for a long while. But what interests me is that initially, people who called time on untramelled growth were called to provide "proof" whereas people who don't believe that a correction is likely or possible don't have to provide any proof at all, or at least, don't have to provide the same level of proof. NCB's report is an indication of this. Many people have doubts about the property market because it has gone over and above average affordability. Not because they are playing guessing games with the economy and future population. What we have now is not a long term situation, and unfortunately, rising salaries will not buy us out of this situation without also buying us a lot of unemployment.
Ultimately, the property market comes down to brass tacks. Who has the money, and who hasn't. The banks are running out of options to give people more money to buy property. I'll be interested to see what they come up with to get over short term affordability problems since they've run out of 100% and interest only and 35 and 40 year terms as options. There isn't much left except very dangerous games in a rising interest rate environment.