In essence, all rent-control policies involve specifying a maximum rent that a landlord may charge for a dwelling  The rationale for controlling rents is to protect tenants in situations where limited supply will cause rents to rise sharply in the face of increased demand
However, although rent control may help some tenants in the short run, it affects the rental-housing market adversely in the long run because landlords become reluctant to maintain the quality of their existing properties and even more reluctant to have additional rental-housing units built
Rent control makes it very difficult for landlords to achieve reasonable returns on any investments in maintenance or in new construction.