(5) Kingdon's research on policy change is instructive for the simple and parsimonious model it presents. It begins with the question (1995, 1), " What makes people in and around government attend, at any given time, to some subjects and not to others?" For Kingdon, the level of analysis is the government agenda and the items government pays attention to, and the unit of analysis is "predecisions," decisions made by relevant actors that affect whether an issue reaches the government agenda. Rather than focus on policy stability, Kingdon is interested in explaining the process by which issues reach the government agenda and allow for significant policy change to take place. To do this, he examined health and transportation policy in the late 1970s, focusing on cases of policy initiation and cases in which policy initiation seemed likely but never occurred.
(6) Analyzing the agenda-setting process and alternative selection, Kingdon incorporated the "garbage can model" of Cohen, March and Olsen(1972). This model is centered on the concept of "organized anarchies" (Kingdon 1995, 84), or organizations that share three general characteristics: problematic preferences, fluid participation, and unclear technology. People routinely move in and out of organizations or organizational subunits and thus rarely understand the organization's purpose or their role within the organization. Various participants work autonomously to provide independent solutions to similar problems. In the process, ideas are jumbled together, with solutions actually searching for problems, rather than the reverse, as would be suggested by the stages model of public policy or the rational comprehensive model(Kingdon 1995, 85). According to the garbage can model, policy entrepreneurs learn by trial and error regarding alternative selection. The end result is that both problems and solutions are "dumped" into the policymaking garbage can. What does this mean for Kingdon's model and the agenda-setting process? In essence, the policy process is not linear nor does it always move in incremental stages. Rather it is best described as relative chaos among competing policy communities. Kingdon revised the garbage can model to include three separate "streams": problems, policies, and politics. Each stream, as we discuss below, contributes to our understanding of why government pays attention to some problems more than others.
(7) The first stream is the problem stream. For policy change to take place, policy actors must first recognize that there is an existing problem. The most obvious way for a condition to become a problem is through a "focusing event." Focusing events are highly public events that call attention to a particular issue. For example, the disaster at Three Mile lsland was a focusing event for nuclear power, ultimately shifting the focus away from energy efficiency to health and safety concerns. "Indicators" such as regularly conducted surveys or published reports can also raise awareness of an existing condition, but focusing events tend to be more effective. The media also plays an important role in shaping the saliency of a particular issue. Again, as other agenda-setting scholars have suggested, policy definition and policy image are crucial to moving a condition onto the government agenda(see Stone 2002).
(8) Policy is the second of Kingdon's streams. It is here where policy alternative are generated to address emerging problems. Participants in the policy stream are represented by both "visible" and "hidden cluster" actors (Kingdon 1995, 199). The visible cluster represents prominent policy actors such as the president and members of Congress. The hidden cluster tends to be composed of policy specialists operating deep within federal or state agencies that set the available alternatives upon which policy decisions are made Like Heclo, Kingdon described the policy entrepreneur as highly influential in the policy process, capable of determining policy outcomes by manipulating and narrowing the number of policy alternatives. This differs from the role of visible participants, who are less effective in the policy stream but more important in the problem stream and in getting items on the government agenda (Kingdon 1995, 30). Kingdon (1995, 116) described the policy stream as consisting of a "policy primordial soup" in which multiple ideas are just "floating" around, waiting to be scooped up by prominent government actors. The primordial soup is akin to the garbage can put forth by Cohen, March, and Olsen (1972). Both problems and solutions get dumped into the same policy can, resulting in an unpredictable process of policy change.
(9) The process of selecting policy alternatives is not random, however. Within the policy stream, Kingdon has argued that there are two important aspects to understanding how alternatives move from the primordial soup to being a viable policy option: l) through "softening up" ; and 2) through "coupling" (1995, 200-201). Policy specialists in the hidden cluster, interest groups, and even academics and researchers can help to soften up the agenda to ensure favorable political receptivity. As Kingdon noted, the softening up process is critical in terms of determining whether a policy actually reaches the government agenda. The coupling process is the ability to link alternatives with problems. For elected officials, policy alternatives must be justified in terms of costs and benefits, with particular attention to core constituencies, and must also be workable solutions to the problem. Although many good ideas may be floating around among policy specialists, without a specific problem, they are unlikely to reach the government agenda.