Riker took on a professorship at Lawrence University in Appleton, Wisconsin, where he published The Theory of Political Coalitions. In 1962, he became the chair of the Political Science Department at the University of Rochester, where he remained chair until 1977, and remained active until his death. Riker founded the now-mainstream field of positive political theory, which introduced game theory and the axiomatic method of social choice theory to political science. Bruce Bueno de Mesquita and Kenneth Shepsle in their memoir write that "These have proved crucial to predictive tests for political theory." Among other contributions, Riker is known for work on the theory and history of federalism and on what he called "heresthetics"—the art of changing political outcomes without changing peoples' underlying preferences by manipulating the decision-making process, for example by changing the order in which decisions are made. In his book Liberalism Against Populism, he argued that the instability of majority rule, demonstrated in Arrow's impossibility theorem and the McKelvey–Schofield chaos theorem, meant that "populist" interpretations of democracy as implementing a collective will of the people were untenable. Instead, democratic leaders aimed to build disparate coalitions; a piece of successful coalition-building could cause realigning elections, in which blocs of voters swiftly changed their allegiance. Concerning political coalition for the benefit of minorities, Riker argued that the larger the coalition, the shorter-lived it is. The William H. Riker Prize for excellence in undergraduate teaching is awarded by the University of Rochester bi-annually in his honor. The Political Economy section of the American Political Science Association awards an annual book prize in his name as well.
Publications
Riker, William H. Soldiers of the States: The Role of the National Guard in American Democracy. Washington, D.C.: Public Affairs Press, 1957.
____. "Towards a Positive Political Theory", Englewood Cliffs, NJ: Prentice Hall, 1973.
____. "Implications from the Disequilibrium of Majority Rule for the Study of Institutions," American Political Science Review, 74, 1980: 432–446.
____. Liberalism Against Populism. San Francisco: W. H. Freeman, 1982.
____. "The Heresthetics of Constitution-Making: The Presidency in 1787, with Comments on Determinism and Rational Choice." American Political Science Review, 78, 1984: 1–16.
____. The Art of Political Manipulation. New Haven: Yale University Press, 1986.
____. The Strategy of Rhetoric. New Haven: Yale University Press, 1996.
