Formal theory (political science)

Formal theory, also known as positive political theory, is the subfield of political science that uses formal methods such as social choice theory, game theory, and statistical analysis to deductively study political phenomena. It seeks to construct and use mathematical models to represent strategic choices in political contexts, such as in elections, legislative policymaking, and international politics. These models can either be tested empirically or used to elucidate real-world political phenomena by highlighting relevant incentives or causal mechanisms.

Much of the original work done in formal theory was motivated by a desire to rigorously explain and analyze political phenomena, in contrast to the emphases on description and value judgment that characterized the discipline of political science before the 1950s. The pursuit of formal theory, its proponents argued, would help make political science more explanatory and predictive and thus more "scientific", helping its scholarship integrate with that of the other social sciences. William H. Riker, the founder of formal theory, wrote of his work:

I describe the field in which I expect to work at the Center as ‘formal, positive political theory.’ By Formal, I mean the expression of the theory in algebraic rather than verbal symbols. By positive I means the expression of descriptive rather than normative propositions…. I visualize the growth in political science of a body of theory somewhat similar to…the neo-classical theory of value in economics. It seems to be that a number of propositions from the mathematical theory of games can be woven into a theory of politics. Hence, my main interest at present is attempting to use game theory for the construction of political theory.

Today, formal theoretic approaches remain influential in political science scholarship, particularly in the American academy and especially at high-ranking university programs and academic journals. However, the subfield has come under a variety of criticisms during its development and history. Some of these include that it has not or cannot be empirically tested, that it merely restates banal truisms using equations, that it lacks any analytical purchase for explaining political phenomena, and that is has no predictive power.

Formal theory is one of the "main" subfields in political science along with American politics, comparative politics, international relations, political economy, political theory, and political methodology. These subfields structure the way research, graduate student instruction, and faculty hiring is done within the discipline at US universities.