(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.