How Building Expensive New Housing Actually Helps Create More Affordable Cities via Gizmodo

“In tight markets, poor and middle­-class households are forced to compete with one another for scarce homes. So new market-rate housing eases that competition, even if the poor are not the ones living in it. Over time, new housing also filters down to the more affordable supply, because housing becomes less desirable as it ages. That means the luxury housing being built today will contribute to the middle-class supply 30 years from now; it means today’s middle-class housing was luxury housing 30 years ago.”