“Utility,” in plain English, means usefulness. In Australia, a ute is a useful vehicle. Jeremy Bentham specialized the meaning to a particular sort of usefulness. “By utility,” he said, “is meant that property in any object, whereby it tends to produce benefit, advantage, pleasure, good, or happiness (all this in the present case comes to the same thing) or (what comes again to the same thing) to prevent the happening of mischief, pain, evil, or unhappiness to the party whose interest is considered” (1823, p. 2). The “principle of utility” is the principle that actions are to be judged by their usefulness in this sense: their tendency to produce benefit, advantage, pleasure, good, or happiness. When John Stuart Mill (1969, p. 213) spoke of the “perfectly just conception of Utility or Happiness, considered as the directive rule of human conduct,” he was using “Utility” as a short name for this principle. “The greatest happiness principle” was another name for it. People who subscribed to this principle came to be known as utilitarians.

When the relative importance of the national exploitation from which a working class suffers through belonging to the proletariat diminishes continually as compared with that from which it benefits through belonging to a privileged nation, a moment comes when the aim of increasing the national income in absolute terms prevails over that of the relative share of one part of the nation over the other. From that point onward the principle of national solidarity ceases to be challenged in principle, however violent and radical the struggle over the sharing of the cake may be. Thereafter a de facto united front of the workers and capitalists of the well-to-do countries, directed against the poor nations, coexists with an internal trade-union struggle over the sharing of the loot. (Emmanuel, 1972, p. 180)

For the past 20 years or so the literature on noncooperative games has been centered on the search for an equilibrium concept that expresses the notion of rational behavior in interactive situations. A basic tenet in this literature is that if a “rational solution” exists, it must be a Nash equilibrium. The consensus view, however, is that not all Nash equilibria can be accepted as rational solutions. Consider, for example, the game of Figure 1.

The application of evolutionary ideas to socioeconomic systems has been an increasingly prominent theme in the work of Friedrich Hayek, and the motif has become dominant in his recent book (Hayek, 1988). In an earlier issue of this journal, Viktor Vanberg (1986) raises two substantive criticisms of Friedrich Hayek' theory of cultural evolution that invoke some important questions concerning use of the evolutionary analogy in social science.

Since a paradigmatic approach is judged in part by the range of phenomena it can explain, neoclassical microeconomists have no doubt gained assurance about the power of their paradigm by the invasion of economics into a number of related fields, what Hirschleifer (1985) has referred to as the “expanding domain of economics.” Moreover, even beyond these excursions into the provinces of other social sciences concerned with human behavior, economics has also recently expanded into the analysis of animal behavior (cf. Battalio, Kagel, and McDonald, 1985). This development not only adds more scientific prestige to the approach, but allows economists to use research techniques developed in more experimentally oriented disciplines.