obstacles: define precisely what constitutes implementation activities, identify the crucial variables for implementation, adopt designs that are comparative and longitudinal, and develop measures of policy changes over time.
Implementation is defined as activities that carry out authoritative public policy directives or mandates. Pressman and Wildavsky ( 1984) classic study stimulated early research on policy implementation. Prior to this time, implementation generally was treated as an automatic process in line with the tenets of the classical model of administration.
Three generations of research characterize the academic literature on implementation. First-generation studies relied on case studies to identify common barriers to effective implementation, providing a pessimistic conclusion regarding the effectiveness of government programs. Second-generation research sought to develop theoretical frameworks to explain or understand the implementation process by utilizing either a top-down or bottom-up perspective. Top-down scholars focus on the gap between the policymakers' intent and bureaucratic action. In contrast, bottom-up research views policy implementation as bargaining or adaptation. The latter approach is consistent with contemporary management theory, which is moving away from centralized bureaucracy toward devolving responsibility to the lowest level of the organization (i.e., empowering the worker). Third-generation research synthesizes components of the top-down and bottom-up approaches in an effort to develop a more complete theoretical framework of policy implementation. Although its proponents see much potential in third-generation research, its contributions have yet to be fully demonstrated.
DAVID J. HOUSTON
Bardach, Eugene, 1977. The Implementation Game: What Happens After a Bill Becomes a Law. Cambridge, MA: MIT Press.
Derthick, Martha, 1972. New Towns in Town. Washington, DC: Urban Institute.
Edwards, George C., III, 1980. Implementing Public Policy. Washington, DC: Congressional Quarterly Press.
Elmore, Richard F., 1979. "Backward Mapping". Political Science Quarterly 94: 601-616.
-----, 1985. "Forward and Backward Mapping: Reversible Logic in the Analysis of Public Policy". In K. Hanf and T. A.J. Toonen, eds., Policy Implementation in Federal and Unitary Systems. Dordrecht: Martinus Nijhoff.
Fox, Charles J., 1990. "Implementation Research: Why and How to Transcend Positivist Methodologies." In Dennis J. Palumbo and Donald J. Calista, eds., Implementation and the Policy Process: Opening Up the Black Box. New York: Greenwood Press.
Goggin, Malcolm L., Ann O'M. Bowman, James P. Lester, and Laurence J. O'Toole, Jr., 1990. Implementation Theory and Practice: Toward a Third Generation. Glenview, IL: Scott, Foresman/ Little, Brown.
Hjern, Benny, 1982. "Implementation Research: The Link Gone Missing." Journal of Public Policy, 2: 301-308.
Lester, James P., Ann O'M. Bowman, Malcolm L. Goggin, and Laurence J. O'Toole, Jr., 1987. "Public Policy Implementation: Evolution of the Field and Agenda for Future Research." Policy Studies Review 7: 200-216.
Lipsky, Michael, 1971. "Street Level Bureaucracy and the Analysis of Urban Reform". Urban Affairs Quarterly 6: 391-409.
Murphy, Jerome T., 1973. "The Education Bureaucracies Implement Novel Policy: The Politics of Title I of ESEA." In Allan P. Sindelar, ed., Policy and Politics in America. Boston: Little, Brown.
O'Toole, Laurence J., Jr., 1986. "Policy Recommendations for Multi-Actor Implementation: An Assessment of the Field." Journal of Public Policy 6: 181-210.
O'Toole, Laurence J., Jr., and Robert S. Montjoy, 1984. "Interorganizational Policy Implementation: A Theoretical Perspective." Public Administration Review 49: 491-503.
Pressman, Jeffrey, and Aaron Wildavsky,  1984. Implementation. 3d ed. Berkeley, CA: University of California Press.
Sabatier, Paul A., 1986. "Top-Down and Bottom-Up Approaches to Implementation Research: A Critical Analysis and Suggested Synthesis." Journal of Public Policy 6: 21-48.
Sabatier, Paul, and Daniel Mazmanian, 1980. "The Implementation of Public Policy: A Framework of Analysis." Policy Studies Journal 8: 538-560.
Van Donald S. Meter, and Carl E. Van Horn, 1975. "The Policy Implementation Process: A Conceptual Framework." Administration and Society 6: 445-488.
IMPLIED POWERS. Prerogatives that, although not specifically enumerated in a constitution, may be inferred from powers expressly granted. For example, the power to institute a draft is a power that is implied from the United States Constitution's enumerated power to raise armies and navies. The doctrine of implied powers under the United States Constitution was most clearly articulated by Chief Justice John Marshall and the United States Supreme Court in the landmark case of McCulloch v. Maryland ( 1819). Their broad interpretation of implied powers was extremely important in the development of the national government and administration of the United States since it limited state encroachments on federal power and allowed government to expand into policy areas not expressly defined by the Constitution. Implied powers have made it possible to retain the United States Constitution largely intact (only 26 amendments), though it was written for a far different, simpler era.
The doctrine of implied powers expanded upon the powers of the national government suggested in essay number 45 of The Federalist Papers (see Rossiter 1961), wherein James Madison wrote, "The powers delegated by the proposed Constitution . . . are few and defined. Those