Every political system must have an agenda if it is to prioritize the problems and issues facing it. Furthermore, this agenda will always be limited in the sense that the range of issues that could deserve attention clearly outnumbers the range of issues that actually get attention. Based on these fundamental observations a rich literature on agenda setting has studied how and why issues rise and fall in importance over time. In this paper we examine the more fundamental question about why the agenda of some political systems are larger than the agenda of other systems. Addressing this question not only teaches us about an important aspect of political systems that has been ignored in previous agenda setting studies; it also holds the potential do identify why high or low issue processing decision making systems are formed.
