Use the concept of economic rent to explain how rent controls could have an effect quite opposite to the intention

Answer 1

Only economic rent can be taxed away without reducing the quantity of the input supplied. A building owner cannot expect to earn economic rent because too many other potential owners whose costs of construction are roughly the same will also offer apartments if rents are high. If the market price temporarily included some economic rent other builders would start new construction that would drive the price down. Thus buildings come rather close to being in perfectly elastic supply. This means that builders and owners of buildings cannot collect economic rent in the long run. Because apartment owners collect very little economic rent, payments by tenants in a free market must be just enough to keep those apartments on the market. If rent controls push these prices down, the apartments will start disappearing from the market. Among other unfortunate results, we can therefore expect rent controls to contribute to homelessness.