Institutions are instruments of stability. Twenty years of research in the “new institutionalism” has produced voluminous studies into how structures constitute or constrain the behavior of actors in political, social, and economic contexts. Agenda controls order and limit the alternatives actors choose from, logics of appropriateness dictate appropriate “scripts” agents follow in structural contexts, learning effects and high initial fixed costs reinforce past choices in ways that restrict future alternatives.Kenneth A. Shepsle, “Institutional Arrangements and Equilibrium in Multidimensional Voting Models,” American Journal of Political Science 23 (1979): 27–59; Paul J. DiMaggio and Walter W. Powell, “Introduction” in The New Institutionalism in Organizational Analysis, ed. Walter W. Powell and Paul J. DiMaggio (Chicago: The University of Chicago Press, 1991); Paul Pierson, “Increasing Returns, Path Dependence, and the Study of Politics,” American Political Science Review 94 (2000): 251–67. In other words, institutions produce stability through “regulative, normative, or cognitive mechanisms” that limit, constitute, or constrain the range of alternatives actors confront.Elisabeth S. Clemens and James M. Cook, “Politics and Institutionalism: Explaining Durability and Change,” Annual Review of Sociology 25 (1999): 441–66.