Kenneth Arrow
138 quotes
Biography
"There is no need to enlarge upon the importance of a realistic theory explaining how individuals choose among alternate courses of action when the consequences of their actions are incompletely known to them. It is no exaggeration to say that every choice made by human beings would meet this description if attention were paid to the ultimate implications."
"Among economic phenomena which have in some way been tied up with the existence of uncertainty, three classes may be distinguished: (1) those which by their very definition are concerned with uncertainty; (2) those which are not related to uncertainty by definition but nevertheless have no other conceivable explanation; (3) those whose relation to uncertainty is more remote and disputable."
"Traditional welfare economics shows that there are certain of these combinations that will be preferred by all the voters, which permits us to eliminate the others without too much discussion. However, there will always remain an irreducible kernel of possibilities among which the choice rests on a combination or aggregation of individual ethical attitudes about distribution."
"Ever since I encountered Hicks’s Value and Capital while I was still a graduate student, I had the aim of completing and extending his vision of the economic system in its purest form. This was not because I believed that the economic world was perfectly competitive or that it was clearly self-equilibrating; after all, Chamberlin, Robinson, and Keynes were dominant intellectual influences, and I had the even more powerful influence of the facts of massive unemployment and large corporations. But the idea that the economic world was a general system, with all parts interdependent, seemed (and seems) to me to be an essential of good analysis. I regret what appears to be a revival of single-market thinking both among monetarists and among some of the younger empirical analysts. Then as now, the only game in town that offered a general system of economic interdependence was general competitive equilibrium, an idea to which the name of Leon Walras is imperishably linked. At least, such a system would provide a starting point for analysis of the market’s imperfections."
"L. Walras first formulated the state of the economic system at any point of time as the solution of a system of simultaneous equations representing the demand for goods by consumers, the supply of goods by producers and the equilibrium condition that supply equal demand on every market."
"Perhaps as important is the relation between the existence of solutions to a competitive equilibrium and the problems of normative or ."
"The government may be regarded as a decision-making entity. Among the decisions it makes are the formation of economic policy and the collection of economic-statistical information. In all modern nations the economic policies of the government are significant activities, if for no other reason than the high proportion of national income which passes through the Treasury; but of course in many countries much more ambitious economic planning is aimed at, though not necessarily achieved. Economic statistics, on the other hand, if one is to judge by expenditures, form only an insignificant proportion of a government's activities and are the least developed precisely in those underdeveloped countries which have the greatest felt needs for economic plans."
"Government economic policy, like almost any realistic decision problem, has two fundamental characteristics: it is sequential and it is uncertain."
"In view of the magnitude of an economic system, it would take only a very small percentage of improvement in economic stability or growth to make almost any conceivable data collection worthwhile. The situation is analogous to reported results of the use of linear programming in industry; the gains are small in proportion to previous profit levels but still very much larger than the costs of the programming. No country is adequate in respect to its data. In particular the underdeveloped countries, with their ambitious programs, might well ponder whether or not the marginal productivity of investment in better economic statistics is perhaps not higher than almost any conceivable alternative; they have more need and fewer data."
"Decision theory, as it has grown up in recent years, is a formalization of the problems involved in making optimal choices. In a certain sense — a very abstract sense, to be sure — it incorporates among others operations research, theoretical economics, and wide areas of statistics, among others."
"The formal structure of a decision problem in any area can be put into four parts: (1) the choice of an objective function defining the relative desirability of different outcomes; (2) specification of the policy alternatives which are available to the agent, or decision-maker, (3) specification of the model, that is, empirical relations that link the objective function, or the variables that enter into it, with the policy alternatives and possibly other variables; and (4) computational methods for choosing among the policy alternatives that one which performs best as measured by the objective function."
"Strictly speaking, decision theory really is concerned only with the fourth part of the division given above, that is, the determination of the computational methods for optimization. Given the determination of the other three factors―the objective function, the range of policy alternatives, and the model―the ideal picture is that someone, presumable the firm that hires the operations researcher, hands him, on a silver platter, an objective function. By talking to the engineers, or by looking into a few scientific laws, he determines the policy alternatives available and also the model."
"Speaking very broadly, almost any human action involves choice; the external environment delimits a range of possible actions at any given moment but does not usually reduce that range to a single alternative. The formulation of a theory of human action in some sphere as a theory of choice means its presentation as a functional relation associating with each possible range of alternatives a chosen one among them."
"Learning, as studied by psychologists, closely resembles sequential analysis in some aspects. Learning experiments usually consist of a series of trials in which the subject’s choices are sometimes rewarded and sometimes not. The individual, after making many choices, eventually begins to discriminate between the proper response and the improper one. At some point, presumably, he could terminate the experiment, at least in the sense of disregarding the further observations and making the same choice each time."
"Index numbers are, of course, desired for purposes other than to measure the cost of living. One obvious possibility is to consider some subset of cost-of- living items, such as food. The logic of the preceding argument goes through precisely provided we assume that the distribution of food expenditures in any period among different foods depends only on the total volume of food expenditures and is independent of the prices of other goods, for any given total volume of food expenditures. This does not deny substitution between foods and other commodities, but we assume that the total effect of this substitution is already reflected in the choice of a volume of food expenditures. In a broad way, similar considerations apply to the pricing of producers’ goods, which should be interpreted as reflecting indirectly consumers’ preferences. However, there is undoubtedly a good deal more in the detailed working out of the theory that has never been developed."
"In a capitalist democracy there are essentially two methods by which social choices can be made: voting, typically used to make ‘political’ decisions, and the market mechanism, typically used to make ‘economic’ decisions. In the emerging democracies with mixed economic systems Great Britain, France, and Scandinavia, the same two modes of making social choices prevail, though more scope is given to the method of voting and to decisions based directly or indirectly on it and less to the rule of the price mechanism. Elsewhere in the world, and even in smaller social units within the democracies, the social decisions are sometimes made by single individuals or small groups and sometimes (more and more rarely in this modern world) by a widely encompassing set of traditional rules for making the social choice in any given situation, for example, a religious code."
"In addition to ignoring game aspects of the problem of social choice, we will also assume in the present study that individual values are taken as data and are not capable of being altered by the nature of the decision process itself. This, of course, is the standard view in economic theory (though the unreality of this assumption has been asserted by such writers as Veblen, Professor J. M. Clark, and Knight) and also in the classical liberal creed. If individual values can themselves be affected by the method of social choice, it becomes much more difficult to learn what is meant by one method’s being preferable to another."
"The problem of measuring utility has frequently been compared with the problem of measuring temperature. This comparison is very apt. Operationally, the temperature of a body is the volume of a unit mass of a perfect gas placed in contact with it (provided the mass of the gas is small compared with the mass of the body). Why, it might be asked, was not the logarithm of the volume or perhaps the cube root of the volume of the gas used instead? The reason is simply that the general gas equation assumes a particularly simple form when temperature is defined in the way indicated. But there is no deeper significance."
"The concept of rationality used throughout this study is at the heart of modern economic analysis, and it cannot be denied that it has great intuitive appeal; but closer analysis reveals difficulties."
"If the total number of alternatives is two, the method of majority decision is a social welfare function which satisfies Conditions 2–5 and yields a social ordering of the two alternatives for every set of individual orderings."
"If there are at least three alternatives which the members of the society are free to order in any way, then every social welfare function satisfying Conditions 2 and 8 and yielding a social ordering satisfying Axioms I and II must be either imposed or dictatorial."
"The idealist doctrine then may be summed up by saying that each individual has two orderings, one which governs him in his everyday actions, and one which would be relevant under some ideal conditions and which is in some sense truer than the first ordering. It is the latter which is considered relevant to social choice, and it is assumed that there is complete unanimity with regard to the truer individual ordering."
"From the point of view of seeking a consensus of the moral imperative of individuals, such consensus being assumed to exist, the problem of choosing an electoral or other choice mechanism, or, more broadly, of choosing a social structure, assumes an entirely different form from that discussed in the greater part of this study."
"In this aspect, the case for democracy rests on the argument that free discussion and expression of opinion are the most suitable techniques of arriving at the moral imperative implicitly common to all. Voting, from this point of view, is not a device whereby each individual expresses his personal interests, but rather where each individual gives his opinion of the general will."
"Invention is here interpreted broadly as the production of knowledge. From the viewpoint of welfare economics, the determination of optimal resource allocation for invention will depend on the technological characteristics of the invention process and the nature of the market for knowledge."