For that explanation to work, the vacant spaces must somehow be excluded from the "prevailing rate" calculation. Perhaps by calculating their rent according to

For that explanation to work, the vacant spaces must somehow be excluded from the "prevailing rate" calculation. Perhaps by calculating their rent according to their asking price - which would, interestingly, give (large-scale, at least) landlords even more incentive to hold a few properties vacant - or perhaps by entirely removing them from the equation. I don't know if GP's description is correct, but if it is then I agree with you (I assume) that $0-income spaces ought to be in some way included in the average.