> As long as housing stock is differentiated in price and quality a shortage can endure even with an increase in total supply (rent controlled units for example

> As long as housing stock is differentiated in price and quality a shortage can endure even with an increase in total supply (rent controlled units for example will always be in short supply regardless of new construction). If you build enough quality housing you end up with old crappy housing being impossible to rent out so it either gets abandoned or redeveloped. If you build enough housing the price floor that is rent control ceases to bind because market rates drop below the floor. There can absolutely be a “shortage” of a given combination of quality and price but that’s like saying there’s a shortage of Peter Norvig talented Computer Scientists who’ll work for $50K a year.