¹ Parsons, Talcott, The Structure of Social Action (Glencoe, Ill. 1949)Google Scholar; The Social System (Glencoe, Ill. 1951)Google Scholar; Essays in Sociological Theory (Glencoe, Ill. 1954)Google Scholar; Structure and Process in Modern Societies (Glencoe, Ill. 1961)Google Scholar.

² See Almond, Gabriel, “Comparative Political Systems,” Journal of Politics xvm, (Aug. 1956), 391–409CrossRefGoogle Scholar; Levy, Marion J. Jr., The Structure of Society (Princeton 1952)Google Scholar; Merton, R. K., Social Theory and Social Structure (New York 1957)Google Scholar; Mitchell, William C., The American Polity (New York 1962)Google Scholar and Sociological Analysis and Politics (Englewood Cliffs, N.J. 1967)Google Scholar; Radcliffe-Brown, A. R., Structure and Function in Primitive Society (Glencoe, Ill. 1952)Google Scholar, etc.

³ See, e.g., Coleman, James S., “Comment on ‘On the Concept of Influence,’” The Public Opinion Quarterly xxvii (Spring 1963), 63–92CrossRefGoogle Scholar; Dahrendorf, Ralf, “Out of Utopia: Toward a Reorientation of Sociological Analysis,” American Journal of Sociology LXIV (September 1958), 115-27CrossRefGoogle Scholar; Class and Class Conflict in Industrial Society (Stanford 1959)Google Scholar; Gouldner, Alvin, “Some Observations on Systematic Theory, 1945-55,” in Zetterberg, Hans L., ed., Sociology in the United States (Paris, 1956)Google Scholar; “Reciprocity and Autonomy in Functional Theory,” in Gross, Llewellyn, ed., Symposium on Sociological Theory (New York 1959)Google Scholar; Harsanyi, John C., “Explanation and Comparative Dynamics in Social Science,” Behavioral Science, v (April 1960), 136-45Google Scholar, “A Bargaining Model for Social Status in Informal Groups and Formal Organizations,” Behavioral Science xi (September 1966), 357-69Google Scholar, “Individualistic versus Functionalistic Explanations in the Light of Game Theory,” in Lakatos, I. and Musgrave, A., eds., Problems in the Philosophy of Science (Amsterdam 1967)Google Scholar; Hempel, Carl G., “The Logic of Functional Analysis,” in Gross, Llewellyn, ed., Symposium on Sociological Theory (New York 1959)Google Scholar; Homans, George C., “Contemporary Theory in Sociology,” in Faris, Robert E. L., ed., Handbook of Modern Sociology (Chicago 1964)Google Scholar; Lockwood, David, “Some Remarks on ‘The Social System,’” British Journal of Sociology vii (June 1956), 134-46CrossRefGoogle Scholar; Rex, John, Key Problems of Sociological Theory (London 1961)CrossRefGoogle Scholar.

⁴ Ibid.

⁵ Dahrendorf, 127, has argued that we cannot use the same theoretical model to analyze social conflicts and to analyze social consensus or cooperation. In actual fact, as modern game theory has shown in analyzing games with mixed interests (where the players' interests are similar in some respects and are dissimilar in other respects), the same theoretical model can handle both conflict and cooperation without any difficulty.

⁶ The von Neumann-Morgenstern approach to game theory does not yield determinate predictions for two-person non-zero-sum games and for n-person games, the two game classes most important for social science applications. Neumann, John von and Morgenstern, Oskar, Theory of Games and Economic Behavior (Princeton 1944)Google Scholar. But later work has overcome this difficulty. See, e.g., Harsanyi, John C., “Bargaining and Conflict Situations in the Light of a New Approach to Game Theory,” American Economic Review, LV (May 1965), 447-57Google Scholar and “A General Theory of Rational Behavior in Game Situations,” Econometrica, xxxiv (July 1966), 613-34Google Scholar.

⁷ See, e.g., Simon, Herbert A., Administrative Behavior (New York 1957)Google Scholar, Models of Man (New York 1957)Google Scholar, “The Executive as Decision Maker,” in Simon, H. A., The Shape of Automation (New York 1965)Google Scholar, “Political Research: The Decision-Making. Framework,” in Easton, David, ed., Varieties of Political Theory (Englewood Cliffs, N.J. 1966)Google Scholar.

⁸ In fairness to traditional “interest theories,” before the emergence of modern game theory the analytical tools needed for answering some of these questions were simply not available.

⁹ For example, Black, Duncan, The Theory of Committees and Elections (Cambridge 1958)Google Scholar; Buchanan, James M. and Tullock, Gordon, The Calculus of Consent (Ann Arbor 1962)CrossRefGoogle Scholar; Coleman, James S., “Collective Decisions,” Sociological Inquiry xxxiv (Spring 1964), 166-81CrossRefGoogle Scholar; Harsanyi, John C., “Measurement of Social Power, Opportunity Costs, and the Theory of Two-Person Bargaining Games,” Behavioral Science, VII (January 1962), 67–80Google Scholar, “Measurement of Social Power in II-Person Reciprocal Power Situations,” Behavioral Science, vii (January 1962), 81–91Google Scholar, “Models for the Analysis of the Balance of Power in Society,” in the Proceedings of the i960 International Congress for Logic, Methodology, and Philosophy of Science (Stanford 1962), 442-62Google Scholar; Kaplan, Morton, System and Process in International Politics (New York 1957)Google Scholar; Olson, Mancur Jr., The Logic of Collective Action (Cambridge, Mass. 1965)Google Scholar; Riker, William H., The Theory of Political Coalitions (New Haven, Conn. 1962)Google Scholar, etc. See also Dahl, Robert A., A Preface to Democratic Theory (Chicago 1956)Google Scholar; Homans, George C., Social Behavior: Us Elementary Forms (New York 1961)Google Scholar; and Thibaut, J. W. and Kelley, H. H., The Social Psychology of Groups (New York 1959)Google Scholar. The last three books make no explicit use of formal rational-choice models, but most of their analysis could be easily restated in these terms.

¹⁰ Modern economic theory (often called neoclassical economic theory in contrast to the classical theory) has considerably relaxed this assumption. Though economic self-interest is still regarded as the dominant motive of economic behavior, it is no longer assumed to be the only important motive.

¹¹ Downs, Anthony, An Economic Theory of Democracy (New York 1957)Google Scholar.

¹² If the number of adjustable parameters of a given theory is as large as (or is even larger than) the number of independent observations available to us, then the fact that the theory is consistent with these observations does not provide a real confirmation for it, because such a theory can always be made consistent with our observations if we choose appropriate numerical values for its parameters. Even if the number of adjustable parameters of the theory is smaller than the number of independent observations, but is only just a little smaller, we cannot ascribe much significance to an agreement between our observations and the theory, because this agreement can easily be a matter of chance. Only if the number of adjustable parameters is much smaller than the number of our observations does an agreement between these observations and our theory represent a true confirmation for the latter, and only in this case can we say that our theory provides an explanation for the observed facts.

¹³ See Harsanyi, John C., “Cardinal Utility in Welfare Economics and in the Theory of Risk-Taking,” Journal of Political Economy LXI (October 1953), 434-35CrossRefGoogle Scholar; “Cardinal Welfare, Individualistic Ethics, and Interpersonal Comparisons of Utility,” Journal of Political Economy, LXIII (August 1955), 309-21Google Scholar; “Ethics in Terms of Hypothetical Imperatives”, Mind, XLVII (July 1958), 305-16Google Scholar.

¹⁴ See Harsanyi, “A Bargaining Model for Social Status.”

¹⁵ Harsanyi, “Explanation and Comparative Dynamics,” 136-37.

¹⁶ I owe this point to Nelson Polsby.

¹⁷ By explaining the “existence” of an institution I mean explaining its emergence at some point of time and its survival ever since.

¹⁸ See section VIII; cf. also Harsanyi, “Explanation and Comparative Dynamics.”