If you're serious about trying to discern the reality of this situation as accurately as possible, the most useful metric I know of to look at is the affordability ratio, assuming you can find a source with genuinely honest, unmassaged data.
To me, the fundamentally important question seems to be: has the ability for the average person to own/rent the average shelter increased, decreased, or stayed constant over time? My opinion on the matter would be the whatever the answer to that question is. I don't happen to know the correct answer but I think a related question, how broadly is wealth distributed throughout the population (completely ignoring the "righteousness" of it), would be helpful in making a good guess at it.