Defined in the SNA as the following group of resident institutional units: (a) all units of central, state, or local government; (b) all social security funds at each level of government; and (c) all nonmarket, nonprofit institutions that are controlled and mainly financed by government units. The sector does not include public corporations, even when all the equity of such corporations is owned by government units. It also does not include quasi-corporations that are owned and controlled by government units. However, unincorporated enterprises owned by government units that are not quasi-corporations remain integral parts of those units and, therefore, must be included in the general government sector.