A state's right to control private activity, including land, for the good of society

State governments use police power to set up a variety of real estate laws, such as (1) street zoning ordinances, which restrict, for example, cemeteries and slaughter houses to certain areas in a city (2) building and health codes (like those that require owner to install ramps for the disabled) and (3) rent control, which limits how much a landlord can raise the monthly rent. Police power also allows the government to take private land, but, unlike eminent domain, the government doesn't have to pay for the property.

See: Zoning ordinance
Compare: Eminent domain