By public administration is meant, in common usage, the activities of the executive branches of national, state, and local governments; independent boards and commissions set up by the congress and state legislatures; government corporations, and certain agencies of a specialized character. Specifically excluded are judicial and legislative agencies within the government and nongovernmental administration.
Herbert A. Simon, Donald W. Smithburg, and Victor A. Thompson. Public Administration, Transaction Publishers, 1950. p. 7