That chart of vacancies is an oversimplification. It's too smoothed. For example the vacancies should have a breakdown into per-month bands. Rentals of not-direct 'apartment' style units should be counted in some other category of profiteering.
Each https://en.wikipedia.org/wiki/Metropolitan_statistical_area in the US should have a graph per major downtown, for suburbs within a given rush hour commute distance (1 hour, 2 hour, 3 hour) and then each state for outlying areas (anything outside of another graph).
Each https://en.wikipedia.org/wiki/Metropolitan_statistical_area in the US should have a graph per major downtown, for suburbs within a given rush hour commute distance (1 hour, 2 hour, 3 hour) and then each state for outlying areas (anything outside of another graph).