Positive political theory or
explanatory political theory is the study of
politics using formal methods such as
social choice theory,
game theory, and
statistical analysis. In particular, social choice theoretic methods are often used to describe and (axiomatically) analyze the performance of rules or institutions. The outcomes of the rules or institutions described are then analyzed by game theory, where the individuals/parties/nations involved in a given interaction are modeled as
rational agents playing a game, guided by self-interest. Based on this assumption, the outcome of the interactions can be predicted as an equilibrium of the game.