Mass. Gen. Laws ch. 121B § 25
It is hereby declared that substandard and decadent areas exist in certain portions of the commonwealth, and that there is not in the commonwealth, within a reasonable distance of the principal centers of employment, an adequate supply of low-rent housing for families of low income; that in certain portions of the commonwealth decent, safe and sanitary housing cannot be provided for families of low income in rural areas at a cost which would warrant private enterprise in the locality or in the same general area to provide an adequate supply thereof; that this situation tends to cause an increase and spread of disease and crime and constitutes a menace to the health, safety, morals, welfare and comfort of the inhabitants of the commonwealth and is detrimental to property values therein; that this situation cannot readily be remedied by the ordinary operations of private enterprise; that a public exigency exists which makes the clearance of substandard or decadent areas and the provision of housing for persons of low income a public necessity; that the clearance of substandard and decadent areas and the provision of housing for persons of low income, or either, constitute a public use for which private property may be acquired by eminent domain and public funds raised by taxation may be expended; and the enactment of sections one to forty-four of this chapter is declared to be a public necessity. Moreover, it is hereby declared that substandard and decadent areas can often be eliminated only by the development of housing of persons of varied economic means in the same project and neighborhood and that any benefit to tenants other than low or moderate income tenants provided under this chapter will be at most incidental to, and no greater than is necessary for, achieving proper housing in appropriate surroundings for low income persons and families.
Mass. Gen. Laws ch. 121B, § 25