> The elevators, for example, will only take residents from the lobby to the Poor Floors and back if there are zero outstanding requests from the Rich Floors; this effectively forces the lower income residents to either walk thirty flights up to reach their units, or else wait forty minutes at rush hour to use the elevators – a pretty thinly veiled analogy to what happens today with commuting inequality.

But here's the kicker: the people on the Rich Floors have to pay more, effectively subsidizing the rent of the people on the Poor Floors.