This document outlines several theoretical approaches to public policy:
1. Institutional theory views public policy as an output of government institutions which give policies legitimacy.
2. Rational theory holds that policymakers should select the policy that maximizes social benefits over costs.
3. The garbage can model critiques rational theory, arguing that organizations function by problems and solutions intersecting unpredictably.
4. Incremental theory sees policy as continuing previous approaches with minimal changes. Other theories discussed include mixed scanning, interest groups, elites, game theory, and public choice. Theories help simplify reality and direct research, though most real policies combine elements of multiple theories.