UNCERTAINTY, EVOLUTION, AND
ECONOMIC THEORY
ARMEN A. ALCHIAN4
University of California at Los Angeles
这是一篇开创性的论文此文令作者顿时名扬经济学界
如果读者以前没有读过或者没有从其它途径习得此文的思想那么毫无疑问这篇五十多年前发表的论文仍具极强的震撼力端午节屈原
此外论文在写作方法上也堪称典范值得再三揣摸仿效
A modification of economic analysis to incorporate incomplete information and uncertain foresight as axioms is suggested here. This approach dispens with “profit maximization”; and it does not rely on the predictable, individual behavior that is usually assumed, as a first approximation, in standard textbook treatments. Despite the changes, the analytical concepts usually associated with such behavior are retained becau they are not dependent upon such motivation or foresight. The suggest
ed approach embodies the principles of biological evolution and natural lection by interpreting the economic system as an adoptive mechanism which choos among exploratory actions generated by the adaptive pursuit of “success” or “profit.” The resulting analysis is applicable to actions usually regarded as aberrations from standard economic behavior as well as to behavior covered by the customary analysis. This wider applicability and the removal of the unrealistic postulates of accurate anticipations and fixed states of knowledge have provided motivation for the study.
The exposition is ordered as follows: First, to clear the ground, a brief statement is given of a generally ignored aspect of “profit maximization,” that is, where foresight is uncertain, “profit maximization” is meaningless as a guide to specifiable action. The constructive development then begins with an introduction of the element of environmental adoption by the economic system of a posteriori most appropriate action according to the criterion of “realized positive profits.” This is illustrated in an extreme, random-behavior model without any individual rationality, foresight, or motivation whatsoever. Even in this extreme type of model, it is shown that the economist can predict and explain events with a modified u of his conventional analytical tools.
学会放弃作文
This phenomenon—environmental adoption—is then fud with a type of individual motivated behavior bad on the pervasiveness of uncertainty and incomplete information. Adaptive, imitative,
and trial-and-error behavior in the pursuit of “positive profits” is utilized rather than its sharp contrast,
4I am indebted to Dr. Stephen Enke for criticism and stimulation leading to improvements in both content and exposition.
the pursuit of “maximized profits.” A final ction discuss some implications and conjectures.
许多人奉最大化原则为信条不过上述简洁明快的引言向我们指出利润最大化原则在不确定的经济环境中是不真实的为此有必要对传统的经济分析方法做出修正我们将在下文领略作者如何从生物进化论获得灵感对经济系统的运行和个体的行为做出别致的却又具有说服力的解释
. “PROFIT MAXIMIZATION” NOT A GUIDE TO ACTION
Current economic analysis of economic behavior relies heavily on decisions made by rational units customarily assumed to be eking perfectly optimal situations5. Two criteria are well known—profit maximization and utility maximization6. According to the criteria, appropriate types of action are indicated by marginal or neighborhood inequalities which, if satisfied, yield an optimum. But the standard qualification usually added is that nobody is able really to optimize his situation according t
o the diagrams and concepts becau of uncertainty about the position and, sometimes, even the slopes of the demand and supply functions. Nevertheless, the economist interprets and predicts the decisions of individuals in terms of the diagrams, since it is alleged that individuals u the concepts implicitly, if not explicitly.
Attacks on this methodology are widespread, but only one attack has been really damaging, that of G.Tintner7. He denies that profit maximization even makes any n where there is uncertainty. Uncertainty aris from at least two sources: imperfect foresight and human inability to solve complex problems containing a host of variables even when an optimum is definable. Tintner’s proof is simple. Under uncertainty, by definition, each action that may be chon is identified with a distribution of potential outcomes, not with a unique outcome. Implicit in uncertainty is the conquence that the distributions of potential outcomes are overlapping8. It is worth emphasis that each possible action has a distribution of potential outcomes, only one of which will materialize if the action is taken, and that one outcome cannot be foreen. Esntially, the task is converted into making a decision (lecting and action) who potential outcome distribution is preferable, that is, choosing the action with the optimum distribution, since there is no such thing as a maximizing distribution.
For example, let each of two possible choices be characterized by its subjective distribution of 5See, e.g., J. Robinson, Economics of Imperfect Competition (London: Macmillan), p. 6, for a strong statement of the necessity of such optimal behavior. Standard textbooks expound esntially the same idea. See also P. Samuelson, Foundation of Economic Analysis (Cambridge: Harvard University Press, 1946).
6In the following we shall discuss only profit maximization, although everything said is applicable equally to utility maximization by consumers.
7“The Theory of Choice under Subjective Risk and Uncertainty,” Econometrica, IX (1941), 298-304; “the Pure Theory of Production under Technological Risk and Uncertainty,” ibid,pp. 305-311; and “A Contribution to the Nonstatic Theory of Production,” Studies in Mathematical Economics and Econometrics (Chicago: University of Chicago Press, 1942), pp. 92-109.
8Thus uncertainty is defined here to be the phenomenon that produces overlapping distributions of potential outcomes.
potential outcomes. Suppo one has the higher “mean” but a larger spread, so that it might result in larger profits or loss, and the other has a smaller “mean” and a smaller spread. Which one is the
maximum? This is a nonnsical question; but to ask for the optimum distribution is not nonn. In the prence of uncertainty –a necessary condition for the existence of profits—there is no meaningful criterion for lecting the decision that will “maximize profit.” The maximum-profit criterion is not meaningful as a basis for lecting the action which will, in fact, result in an outcome with higher profits than any other action would have, unless one assumes nonoverlapping potential outcome distributions. It must be noticed that the meaningfulness of “maximum profits—a realized outcome which is the largest that could have been realized from the available actions”—is perfectly consistent with the meaninglessness of “profit maximization”—a criterion for lecting among alternative lines of action, the potential outcomes of which are describable only as distributions and not as unique amounts.数字集成电路
This crucial difficulty would be avoided by using a preference function as a criterion for lecting most preferred distributions of potential outcomes, but the arch for a criterion of rationality and choice in terms of preference functions still continues. For example, the u of the mean, or expectation, completely begs the question of uncertainty by disregarding the variance of the distribution, while a “certainty equivalent” assumes the answer. The only way to make “profit maximization” a specially meaningful action is to postulate a model containing certainty. Then the question of the predictive and explanatory reliability of the model must be faced.9
利润最大化不是一个行为准则尽管许多经济分析宣称人们通过调整行为使收益与成本
在边际上相等就可以达到利润或效用的最大化但是事实上并没有人真正按照图表或曲线来最优化自己的处境阿尔钦认为人们对那最优的一点位于何处是不确定的甚至于他的供求函数也是不确定的在不确定条件下人们可能采取的每一行为都与一系列可能结果的概率分布而不是唯一确定的结果相联系因此当人们面对多种选择每种选择的可能结果具有不同均值和方差问哪一个结果最大是没有意义的我们只能从中选择具有最优分描写山水的古诗句
布的行为当然人们有可能实现最大的利润但是却不可能最大化他的利润
在这一小节中作者分析了利润最大化原则失效的原因指出最大化模型预测与解释的可
二板市场
靠性值得怀疑那么作者下一步如何对这一模型做出修正呢或者还是提出新的模型对经济行为做出解释呢
吊炸天的网名
. SUCCESS IS BASED ON RESULTS, NOT MOTIV ATION
There is an alternative method which treats the decisions and criteria dictated by the economic system as more important than tho made by the individuals in it. By backing away from the trees—the optimization calculus by individual units—we can better discern the forest of impersonal
9Analytical models in all sciences postulate models abstracting from some realities in the belief that derived predictions will still be relevant. Simplifications are necessary, but continued attempts should be made to introduce more realistic assumptions into a workable model with an increa in generality and detail (e M. Friedman and L. Savage, “The Utility Analysis of Choice Involving Risks,” Journal of Political Economy, LVI, No. 4 [1948], 279).
market forces.10This approach directs attention to the interrelationships of the environment and the
prevailing types of economic behavior which appear through a process of economic natural lection. Yet it does not imply that individual foresight and action do not affect the nature of the existing state of affairs.
In an economic system the realization of profits is the criterion according to which successful and surviving firms are lected. This decision criterion is applied primarily by an impersonal market system in the United States and may be completely independent of the decision process of individual units, of the variety of inconsistent motives and abilities, and even of the individual’s awareness of the criterion. The reason is simple. Realized positive profits, not maximum profits, are the mark of success and viability. It does not matter through what process of reasoning or motivation such success was achieved. The fact of its accomplishment is sufficient. This is the criterion by which the economic system lects survivors: tho who realize positive profits are the survivors; tho who suffer loss disappear.
The pertinent requirement—positive profits through relative efficiency –is weaker than “maximized profits,” with which, unfortunately, it has been confud. Positive profits accrue to tho who are better than their actual competitors, even if the participants are ignorant, intelligent, skilful, etc. the crucial element is one’s aggregate position relative to actual competitors, not some hypothetically pe
rfect competitors. As in a race, the award goes to the relatively fastest, even if all the competitors loaf. Even in a world of stupid men there would still be profits. Also, the greater the uncertainties of the world, the greater is the possibility that profits would go to venturesome and lucky rather than to logical, careful, fact-gathering individuals.
两面三刀什么意思The preceding interpretation suggests two ideas. First, success (survival) accompanies relative superiority; and, cond, it does not require proper motivation but may rather be the result of fortuitous circumstances. Among all competitors, tho who particular conditions happen to be the most appropriate of tho offered to the economic system for testing and adoption will be “lected” as survivors. Just how such an approach can be ud and how individuals happen to offer the appropriate forms for testing are problems to which we now turn.11
阿尔钦转换了观察角度他的注意力不在于个体优化行为而在于经济环境内部的相互联系他认为经济系统的运行是一个经济自然选择的过程而一个经济社会普遍占优的经济行为
类型正是经济自然选择的结果那么经济自然选择的原则是什么呢作者认为经济系统只承认正利润而不管个体的决策过程也不管个体动机为何能力如何甚至个体是否意识到这一准则的存在实现正利润而不
彩色汤圆
是最大利润是成功和生存能力的标志因此只有
10In effect, we shall be reverting to a Marshallian type of analysis combined with the esntials of Darwinian evolutionary natural lection.
11Also suggested is another way to divide the general problem discusd here. The process and rationale by which a unit choos its actions so as to optimize its situation is one part of the problem. The other is the relationship between changes in the environment and the conquent obrvable results, i.e., the decision process of the economic society. The classification ud in the text is cloly related to this but differs in emphasizing the degree of knowledge and foresight.
那些实现正利润者才能生存而未实现者将消失
正利润通过相对绩效获得这与赛跑的情况类似奖杯只给跑得相对最快者即使是所有的参赛者都是懒汉同时他还指出世界的不确定性程度越大利润就越可能由爱冒险和幸运的个体获得而不是由那些理智小心爱好收集事实的个体获得因此有的时候成功或生存更有可能由有利的环境决定而不是由正确的动机决定在所有竞争的参与者中那些恰好拥有有利条件的个体被选择为生存者接下来作者下一步要解决的问题是这种经济选择的方法是具体如何运用的个体又是如何碰巧提供适当的条件供经济系统进行选择
. CHANCE OR LUCK IS ONE METHOD OF ACHIEVING SUCCESS
Sheer chance is a substantial element in determining the situation lected and also in determining its appropriateness or viability. A cond element is the ability to adapt one’s lf by various methods to an appropriate situation. In order to indicate clearly the respective roles of luck and conscious adapting, the adaptive calculus will, for the moment, be completely removed. All individual rationality, motivation, and foresight will be temporarily abandoned in order to concentrate upon the ability of the environment to adopt “appropriate” survivors even in the abnce of any adaptive behavior. This is an apparently unrealistic, but nevertheless very uful, expository approach in establishing the attenuation between the ex post survival criterion and the role of the individual’s adaptive decision criterion. It also aids in asssing the role of luck and chance in the operation of our economic system.
Consider, first, the simplest type of biological evolution. Plants “grow” to the sunny side of buildings not becau the “want to ” in awareness of the fact that optimum or better conditions prevail there but rather becau the leaves that happen to have more sunlight grow faster and their feeding syste
ms become stronger. Similarly, animals with configurations and habits more appropriate for survival under prevailing conditions have an enhanced viability and will with higher probability be typical survivors. Less appropriately acting organisms of the same general class having lower probabilities of survival will find survival difficult. More common types, the survivors, may appear to be tho having adapted themlves to the environment, whereas the truth may well be that the environment has adopted them. There may have been mo motivated individual adapting but, instead, only environmental adopting.
A uful, but unreal, example in which individuals act without any foresight indicate the type of analysis available to the economist and also the ability of the system to “direct” resources despite individual ignorance, assume that thousands of travelers t out from Chicago, lecting their roads completely at random and without foresight. Only our “economist” knows that on but one road are there and gasoline stations. He can state categorically that travelers will continue to travel only on that road; tho on other roads will soon run out of gas. Even though each one lected his route at random, we might have called tho travelers who were so fortunate as to have picked the right road wi, efficient, foresighted, etc. of cour, we would consider them the lucky ones. If gasoline supplies were now moved to a new road, some formerly luckless traveler again would be able to mo
ve; and a new pattern of travel would be obrved although none of the travelers had changed his particular path. The really possible paths have changed with the changing environment. All that is needed is a t of
