This landmark national study of the extent and impact of condominium and cooperative conversions promises to be of major policy and program significance. The recent growth of condominium and cooperative conversions is a response to basic changes in the Nations social and housing market conditions which, in its course, helps some and hurts others. For this reason, conversion has sparked considerable controversy --a controversy exacerbated by the shortage of information about what is taking place. This report, prepared in response to a Congressional directive, presents the results of a multi-faceted study designed to provide this information. It documents the present and probable future extent and location of conversions, the factors contributing to their increasing numbers, and their effects-- on people, neighborhoods, and communities. As will be apparent, the scope, causes, and consequences of the conversion phenomenon are, in many ways, quite different than is generally understood.Conversion changes the legal form of a multi-family rental property from single ownership by a landlord to multiple ownership. In most condominium conversions, the landlord first sells the property to a developer specializing in conversion who then sells the individual units. Most conversions are accompanied by some minor or cosmetic improvements to the propertys condition, equipment, or amenities; however, a few conversions have involved the substantial rehabilitation of older buildings.