Structural mechanisms affecting policy subsystems activity: beyond individual and group behavioral propensities in policy design and policy change

Policy sectors constitute distinct policy regimes consisting of the current collectively accepted definition of an issue, the current relevant policies (laws, regulations, fiscal instruments, government programs and relationships), and the actors and institutions (both inside and outside government) actively engaged in implementing and modifying them (Harris and Milkis, 1989; Eisner, 1994a, 1994b). These regimes are constructed at the “subsystem” level (McCool, 1998), that is, as subsets of political, social and economic systems and the various actors and activities of which those are comprised. According to Sabatier (1998, p. 99), “[a] subsystem consists of actors from a variety of public and private organizations who are actively concerned with a policy problem or issue, such as agriculture, and who regularly seek to influence public policy in that domain.” Such subsystems, he argued, provide “the most useful unit of analysis for understanding the overall policy process,” superior to the use of other units such as government organizations or programs. How these subsystems operate and what impact they have on policies and vice versa is a long-standing question in the policy sciences (Cater, 1964). Often these subsystems are viewed as examples of a general class of stable “homeostatic” systems that are self-adjusting or self-equilibrating in routine circumstances and often thought of as changing only under the pressure of external shocks or “jolts” that introduce new extraneous elements into the system, throwing them out of equilibrium (Sabatier, 1988; Aminzade, 1992). This notion of the exogenous nature of subsystem change focuses analytical attention on the various types of external crises that could provoke changes in