Agendas and the Control of Political Outcomes

A considerable theoretical literature argues that if everyone votes sincerely, then an agenda setter has near dictatorial influence on final outcomes, whereas if everyone votes strategically, then an agenda setter's power is considerably reduced. This literature assumes that all feasible agendas are of a special type called amendment agendas. But actual legislative and committee agendas—notably those found in Congress—often are not of this type. Once we expand the domain of feasible agendas to include all types allowed by common parliamentary practice, the influence of agendas on legislative outcomes expands, even with strategic voting. Besides showing with counterexamples that previous results do not extend to a more realistic domain of agendas, we prove some theorems that specify the limits (such as they are) of an agenda setter's power.