哈耶克：知识在社会中的运用
一
当我们努力建构一种合理的经济秩序（a rational economic order）的时候，我们想解决什么问题呢？根据人们熟知的某些假设，这个问题的答案是十分简单的。假设我们拥有所有相关的信息，假设我们能够从一个给定的偏好系统（a given system of preferences）出发，又假设我们掌握了有关可资使用的手段或资源的全部知识，那么剩下的问题也就只是一个纯粹的逻辑问题了。这就是说，对什么是可资使用的手段或资源的最佳用途这个问题的答案，已经隐含在我们的上述假设之中了。解决这个最优问题（this optimum problem）所必须满足的那些条件已经完全设定了，因此我们可以经由数学的形式而得到最佳的陈述；用最简洁的话来说，这就是：任何两个商品或任何两个要素间的边际替换率（the marginal rates of substitution）在它们所有不同的用途中都必定是相同的。
然而需要强调指出的是，这根本就不是社会所面对的那种经济问题。再者，我们为解决这个逻辑问题而发展起来的经济运算方法也没有为我们解决社会经济问题提供某种答案，尽管这种经济运算方法仍不失为我们在解决这个问题的方向上所迈出的重要一步。这种经济运算方法的发现之所以无法解决社会经济问题，其原因在于：作为这种经济运算方法之出发点的“数据”或“基据”（datum），就整个社会而言，对于一个能够计算其结果的单一心智来说，从来就不是“给定的”，而且也绝不可能是如此给定的。
合理经济秩序的问题所具有的这种独特性质，完全是由这样一个事实决定的，即我们必须运用的有关各种情势的知识（the knowledge of the circumstances），从来就不是以一种集中的且整合的形式存在的，而仅仅是作为所有彼此独立的个人所掌握的不完全的而且还常常是相互矛盾的分散知识而存在的。因此，社会经济问题就不只是一个如何配置“给定”资源的问题——当然，“给定”（given）在这里意味着那些资源对于一个按照刻意方式去解决由这些“基据”所设定的某个问题的单一心智来说是“给定的”。据此我们也可以说，社会经济问题毋宁是这样一个问题，即人们如何才能够确使那些为每个社会成员所知道的资源得到最佳使用的问题，也就是如何才能够以最优的方式把那些资源用以实现各种唯有这些个人才知道其相对重要性的目的的问题。简而言之，它实际上就是一个如何运用知识——亦即那种在整体上对于任何个人来说都不是给定的知识——的问题。 我以为，人们在晚近对经济理论所提出的诸多修正方法——尤其是许多运用数学的新方法——并没有阐明上述基本问题的特性，反而遮蔽了它的特性。尽管我在本文中主要关注的是如何合理组织经济的问题，但是在讨论的过程中，我却不得不反复论及这个问题与某些方法论问题（methodological questions）之间所具有的紧密关系。实际上，我希望在本文中阐明的许多论点，乃是各不相同的论证路径在未预期的情形下已然达致的结论。但是，从我现在对这些问题的认识来看，这种情形绝不是偶然的。我认为，当下发生的许多关于经济理论和经济政策的争论，实际上都源于人们对社会经济问题之性质的误解；而这种误解的产生，则是因为人们把自己在处理自然现象时养成的思维习惯误置于社会现象的做法所致。
二
在日常语言中，我们一般都把一整套有关配置我们可资使用的资源的相互关联的决策称之为“计划”（planning）。在这个意义上讲，所有的经济活动都是计划；此外，在众人共处合作的社会中，这种计划不管是由谁制订的，在一定程度上都必须以最初并非为计划者所知道而是为某个其他人所知道的､尔后又以某种方式传递给计划者的那种知识为基础。把这种知识——亦即人们制订计划时赖以为基础的那种知识——传递给计划制订者的各种方式，对于任何解释经济过程的理论来说，都是一个至，关重要的问题；再者，究竟什么方式才是运用最初由个人分散掌握的那种知识的最佳方式的问题，至少在一定程度上讲，也是经济政策——或者是设计一个有效的经济制度——方面的主要问题之一。
对这个问题的回答，实是与这里所存在的另一个问题——亦即应当由谁来制订计划的问题——紧密相关的，而这正是所有有关“经济计划”（economic planning）之争论所围绕的核心问题之所在。争论的关键之处并不在于是否应当制订计划，而毋宁在于应当由谁来制订计划：是由一个中央权力机构以集权的方式为整个经济系统制订计划，还是由许多个人以一种分散的方式制订计划？人们在当下的争论中所使用的那个具有特定意义的“计划”——术语，一般都是意指中央计划，亦即根据一项统一的计划来指导整个经济系统。另一方面，竞争则意味着由许多独立且分立的个人以一种分散的方式制订计划。这二者之间的居间性方案则是把计划交由有组织的行业——或垄断者——去制定；尽管有许多人都在谈论这种方案，但是当他们真的看到这种情况的时候，他们却不再喜欢这项方案了。
关于这三种制度当中哪一种制度有可能更具效率的问题，将在很大程度上取决于我们究竟在哪一种制度中能够期望现有的知识得到最为充分的运用；然而，我们究竟在哪一种制度中能够期望现有的知识得到最为充分的运用这个问题，则又取决于我们在下述两种做法中采取何种做法才更可能取得成功：一是把所有应当加以运用的但最初却由许多不同的个人分散掌握的知识交由某个中央权力机构去处理；二是把个人为了使自己的计划得以与其他人的计划相应合而需要的那种相关的额外知识都传输给这些个人。
三
就此而言，不同种类的知识的地位显然是不同的。因此，对我们这个问题的回答，将在很大程度上取决于不同种类的知识所具有的相对重要性：是那些较可能为特定的个人所掌握的知识更重要，还是那些我们应当较具信心地期望可以为那些经由适当方式挑选出来的专家所组成的某个权力机构所掌握的知识更重要呢？如果说人们在今天普遍认为后一种知识更重要，那只是因为这样一个事实所致：一种知识，亦即科学知识（scientific knowledge），在当下公众的想象中占据了太重要的地位，以至于他们忘记了这样一个道理，即科学知识并不是唯一与此相关的一种知识。我们可以承认，就科学知识而言，一群经由适当方式挑选出来的专家也许可以最好地掌握可资获得的所有最佳的知识——尽管这种做法只是把这方面的困难转嫁到了如何挑选专家这个问题上面。在这个方面，我想指出的乃是这样一个要点：即使我们假设这个问题很容易就可以得到解决，它也只是那个所涉范围更广泛的问题中的一个很小的部分而已。
一如我们所知，在今天，谁要是宣称科学知识不是全部知识的总括，那他就肯定会被认为是在宣扬类似于异端邪说的东西。然而我们只要稍加思索就会发现，现实生活中无疑还存在着一种极其重要但却未经系统组织的知识，亦即有关特定时空之情势的那种知识（the knowledge of the particular circumstances of time and place）——它们不可能被称为科学知识（也就是一般性规则之知识那种意义上的科学知识）。正是在这个方面，每个人实际上要比所有的其他人都更具有某种优势，因为每个人都掌握着有可能极具助益的独一无二的信息，但是只有当立基于这种信息的决策是由每个个人做出的或者是经由他的积极合作而做出的时候，这种信息才能够得到运用。
就此而言，我们只需要牢记下述几点，我们就能够理解这个道理了：第一，无论我们从事什么职业，我们在接受理论训练以后都必须学习许多其他的东西；第二，学习和掌握各种特定工作的知识，实际上耗用了我们整个工作生涯中的很大一部分时间；第三，在各行各业中，有关人的知识､有关当地环境的知识､有关特定情势的知识，都是一笔极其宝贵的财富。了解并操作一架未得到充分使用的机器､掌握并使用某个人所具有的可以得到更佳运用的技艺，或者意识到供应品中断期间所能依凭的供应品储备，从社会的角度来看，与了解并掌握更好的可供选择的其他技术有着大体同样的助益作用。一个靠不定期货船的空程或半空程运货谋生的人，或者一个几乎只知道瞬间即逝之机会的地产掮客，或者一个从商品价格在不同地方的差价中获利的套利人，都是以他们所具有的有关其他人并不知道的那些一瞬即逝之情势的特殊知识为基础而在社会中发挥极大作用的。
令人感到奇怪的是，这样一种知识在今天却遭到了人们普遍的蔑视，而且任何因拥有这种知识而占据了较佳位势（亦即比那些掌握着更多理论知识或技术知识的人占据了更佳位势）的人居然也被认为是行为不端的人。那些因更了解通讯或运输这类设施而占据优势地位的人，有时候也会被认为是不诚实的人，尽管社会运用这个方面的最佳机会与它使用最新的科学发现有着大体同等重要的意义。这种偏见在相当大的程度上造成了人们重生产轻商业的态度。即使那些自以为完全不会受有些论者在过去所主张的赤裸裸的唯物主义谬论之影响的经济学家，在处理那些旨在获得这种实践性知识（practical knowledge）的活动的问题上，也屡犯同样的错误——这显然是因为在他们的研究体系当中，所有这样的知识都被设定为是“给定”的。当下普遍流行的一种看法似乎认为，所有这样的知识都应当理所当然地极容易地为每个人所掌握；而且那种旨在反对现行经济秩序的毫无道理的指责也常常是以这类知识并非如此容易为人们所获得这个事实为基础的。然而需要指出的是，这种观点却忽视了这样一个事实，即我们究竟通过何种方法才能使这类知识尽可能广泛地为人们所获得这个问题，正是我们必须努力加以解决的问题。
四
如果说竭力贬低有关特定时空之情势的知识的重要性乃是当今一种时尚的话，那么这种情形实是与变化（change）本身的重要性在今天蒙遭贬低这个事实紧密联系在一起的。的确，一些变化的发生必定会要求人们对生产计划做出重大的修正；然而，就这些变化的重要性和频繁性而言，“计划者”（通常都是以一种不甚明确的方式）做出的假设与其反对者所做的假设却差别甚大，因为“计划者”的假设完全忽略了这一点。当然，如果人们事先就能够制定出时间跨度较长且事无巨细的经济计划并使之得到严格的实施和遵循，从而不再需要制定任何重大的经济决策，那么制定出一项调整一切经济活动的总体计划的任务也就容易多了。
我们也许有必要强调指出，经济问题始终是由变化所引发的，而且也唯有变化才会产生经济问题。如果事情一成不变或者至少按照人们的预期那样去发展，那么也就不会产生任何需要进行决策（即制定一项新计划）的新问题了。如果有人认为变化——至少是日常的调整措施——在现代社会已经变得不甚重要了，那么他无异于是在主张，经济问题也已变得不太重要了。出于这个缘故，那些坚信变化的重要性正日渐降低的人，通常也就是那些宣称经济方面的因素因为技术知识变得日趋重要而退居次位的人。
在现代生产拥有精密仪器的情况下，是否就真的只有在建立一家新工厂或引进一种新的生产工序的时候才偶尔需要进行经济决策呢？一旦一家工厂落成，所有剩下的问题是否就真的只是些可以由该家工厂的性质所决定的技术问题了，而且也不再需要做什么变动就足以适应日益发生的不断变化的情势了？ 的确，有相当多的人都对上述问题给予了肯定的回答。然而根据我的考察，他们所做的这种回答却是得不到商人或企业经营者所具有的实践经验证明的。在一个竞争的行业中（单单这样一个行业就能够起到一项检测的作用），避免成本上升这项任务要求人们做出持之不懈的努力，而我们知道，仅此一项任务就会消耗掉经理们的一大部分精力。一个低效无能的经理浪费掉作为获利之基础的差别成本（the differentials）实在是太容易不过了；此外，即使技术设施相同，生产成本也可能极不相同。我们可以说，所有上述情况都是商业领域中的常识，但是从经济研究的文献来看，经济学家却好像并不熟知这些情况。一如我们所知，生产厂商和工程师们始终都渴望能够在不受货币成本这类因素制约的情况下进行他们的生产工作，而他们对此欲求的强度，恰恰证明了这些因素涉入他们日常工作的程度。
经济学家之所以越来越容易忘记众多构成整个经济系统的持续发生的小变化，其间的一个原因很可能是他们越来越着迷于统计上的综合指标，而这种综合指标肯定会比具体细小的运动表现出更大的稳定性。然而，这种综合指标的相对稳定性却不能——正如统计学家往往倾向于做的那样——通过“大数定律”（the law of large numbers）或随机变化的相抵方式而得到说明。因为就统计而言，我们必须处理的那些因素，虽说数量很大，但是却没有大到足以使这样的偶然性力量产生稳定性。商品和服务的持续流动之所以能够得以维续，实是因为下述情形所致：第一，人们持续不断地进行着精心的调整；第二，人们每天都在根据前一天所不知道的情势做出新的安排；第三，一旦某人不能交付商品或提供服务，另一个人即刻就会顶掉他的位置。更有甚者，一些高度机械化的大工厂之所以能够保持持续运转，在很大程度上也是因为它们能够依靠外部环境或其他企业提供的服务而满足各种始料不及的需求，比如说盖屋顶的瓦､文具或表格纸，以及这些工厂无力自己生产的但是根据这些工厂的运作计划却是它们所需要的而且也很容易在市场上购买到的各种设备。 在这个问题上，我也许还应当简要地论及这样一个事实：我在上文中所关注的那种知识，因其性质的缘故而不可能进行统计，从而也无法以统计的形式传递给任何一个中央权力机构。因此，这样一种权力机构所必须加以使用的统计数字，也就不得不通过下述方式去获得：对事物间的细小差别进行抽象，亦即以一种有可能对具体决策产生重大影响的方式把那些在地点､品质和其他特定方面不尽相同的项目加以综合并将它们视作同一个种类的资源。据此我们可以得出这样两个结论：第一，以统计信息为基础的中央计划，因其性质的缘故而无力直接对这些具体时空中的情势进行考虑；第二，中央计划者将不得不去发现某种其他的方法，从而使“当事者”或“现场的人”（man on the spot）能够根据具体时空中的情势进行决策。
五
如果我们大家都赞同社会经济问题主要是一个迅速适应特定时空之情势的变化的问题，那么我们就可以由此而推知：必须由那些熟悉这些特定情势的人——亦即那些直接了解相关变化以及即刻可以被用来应对这些变化的资源的人——做出最终的决策。我们根本就不能指望这个问题可以通过另一种方式得到解决：先把所有这样的知识都传递给某个中央机构，并在这个中央机构整合了所有这类知识以后再发布命令。因此，我们只能够经由某种非集权化的方式来解决这个问题。但是，这只回答了我们问题当中的一个小问题。我们之所以必须采取非集权化的方式，实是因为我们唯有依此方式才能够确使那种有关特定时空之情势的知识得到及时的运用。然而需要指出的是，“当事者”也无法只根据他自己所拥有的有关周遭环境之事实的有限但却直接的知识进行决策。因此，这里依旧存在着这样一个问题，即在“当事者”试图使他的决策与更大经济系统的整个变化模式相应合的时候，人们如何才能够把他所需要的更多的其他信息传递给他呢？
“当事者”究竟需要多少知识才能够成功地做到这一点呢？在他的直接知识视域以外的诸多事件中，究竟哪些事件与他的即时性决策具有相关性呢？此外，他究竟需要了解其中的多少事件呢？
世界上所发生的任何一起事件几乎都可能对“当事者”应当做出的决策产生某种影响。但是他却毋需直接了解这些事件本身，也毋需直接了解这些事件所具有的全部影响。对于“当事者”来说，下述情况的发生乃是无关宏旨的：为什么在一个特定的时间内某种尺寸的螺丝钉有较大的需求；为什么纸袋要比帆布袋更容易搞到；为什么熟练工人或某些特定的机床在眼下很难买到，等等。实际上，对他有意义的只是这样一个问题：与买到他关心的其他东西相比较，买到这些东西究竟是难还是易，或者他所生产的或使用的替代品究竟在多大程度上为人们所急需或在多大程度上不为人们所急需。因此，他所关注的始终是一个有关特定事物之相对重要性的问题；但是，他却毋需对那些会改变这些事物之相对重要性的原因予以关注，除非它们对他周围的那些具体事物产生了影响。
正是在这个方面，我在上文中称之为“经济运算”的方法（或纯粹的选择逻辑方法）至少能够通过类推的方式帮助我们认识到价格体系据以解决（事实上正在解决）这个问题的方式。即使是一位掌握了某个自给自足的小规模经济系统之全部数据的控制者，也无法彻底弄清楚每次对资源配置做某种微小调整时那些有可能受到影响的目的与手段之间的全部关系。的确，纯粹选择逻辑方法的伟大贡献就在于它极其明确地阐述了这样一个道理：即使这样一位控制者想解决这种问题，也唯有通过建构并不断使用等值比率（或“值”或“边际替换率”）这样的方法——也就是给每一种稀缺资源都标上一个数字指标的方法：这种指标不可能从某种特定的资源所具有的任何特性中推演出来，但是它却可以反映出（或者可以集中体现出）这种特定资源在整个手段——目的结构（the whole means-ends structure）中所具有的重要意义。在任何微小的变化中，这种控制者都只能够去考虑那些集中了所有相关信息的量化指标（或“值”）；而且也唯有通过逐个调整这些量值的方法，他才能够恰当地重新安排他的措施，而毋需从头去解决整个问题，亦毋需在任何阶段上同时考察它的所有方面。
从根本上讲，在一个有关相关事实的知识（the knowledge of the relevant facts）由众多个人分散掌握的系统中，价格能够帮助不同的个人协调他们所采取的彼此独立的行动，就像主观价值（subjective values）可以帮助个人协调他所制定的计划的各个部分一样。就此而言，我们有必要先对一个极其简单且常见的有关价格体系之作用的事例做一番讨论，并据此探明价格体系所具有的切实作用。我们不妨假设这样一种情况：世界某地出现了一种使用某种原材料——例如锡——的新机会，或者有一处锡的供应源已然耗尽。显而易见，上述两种原因当中究竟哪种原因造成了锡的紧缺，对于锡的用户来说并不重要——这一点意义非常重大。在这种情况中，锡的用户只需要知道，他们以前一直消费的那部分锡，现在用在其他地方可以盈利更多，因此他们必须节约用锡。对于绝大多数的锡用户来说，甚至都没有必要知道什么地方对锡有更大的需求或者节约用锡究竟可以满足什么样的其他需求。只要其中的一些锡用户直接了解到了这种新的需求并把这种资源转用于这种新的需求方面，而且只要那些意识到由此产生的新缺口的人转而寻求其他资源来填补这个缺口，那么他们所采取的这种做法的影响就会迅速扩及整个经济系统。当然，这种情况不仅会影响到锡的用途，而且也会影响到锡的替代品的用途以及这些替代品的替代品的用途，影响到所有锡制品的供应以及它们的替代品的供应，等等。然而，所有上述影响实际上都是在绝大多数提供这些替代品的人对这些变化的最初原因毫无所知的情况下发生的。显而易见，整个上述情形构成了一个市场，但是这个市场的形成却并不是因为该领域中的每一个成员都洞见到了其间的所有情况所致，而是因为他们有限的个人视域是紧密关联的和相互交搭的，因此相关的信息可以经由许多中介而传递给所有的成员。由此可见，任何商品都有一个价格（更确切地说，地方各项价格之间的关系乃是由运输成本等因素所决定的）这个事实本身，就构成了某种解决办法；当然，一个控制者在掌握了所有这方面的信息以后也可能达致这种解决办法，但是这里的问题在于：任何个人都不可能掌握所有这方面的信息，因为它们事实上是由所有涉入这一过程之中的个人分散掌握的。
六
如果我们想理解价格体系（the price system）的真正作用，那么我们就必须把价格体系视作是这样一种交流信息或沟通信息的机制。当然，价格越僵化，价格体系所具有的这种作用也就越有限。（然而，甚至当公布价格[quoted prices]变得相当僵化的时候，那些经由价格变化而发挥作用的各种力量在很大程度上仍将通过契约的其他条款而发挥作用。）就价格体系而言，最具重要意义的一个事实便是它的运转所需依凭的知识很经济；这就是说，涉入这个体系之中的个人只需要知道很少的信息便能够采取正确的行动。一如我们所知，唯有那些最关键的信息才会以一种极为简洁的方式（亦即通过某种符号的方式）传递给他人，而且只传递给有关的人士。把价格体系描述成一种记录变化的工具或一种电信系统（a system of tele communications）并不只是一种比喻，因为这种电信系统能够使单个生产者仅通过观察若干指标的运动（就像工程师观察若干仪表的指针那样）就可以根据各种变化去调整他们的活动——当然，他们所了解的变化也只是反映在价格运动中的那些变化而已。
当然，这些调整活动很可能永远都无法达致“完善的”或“完全的”（perfect）程度，尽管一些经济学家在均衡分析中认为它们是“完善的”或“完全的”。但是，我颇感担忧的是，我们所养成的那些根据几乎所有的人都具有大体“完善的”或“完全的”知识（perfect knowledge）这一假设来处理这个问题的理论研究习惯，在一定程度上会使我们无法洞见到价格机制的真正作用，而且还会致使我们在判断价格机制之效力的时候采用一些颇具误导性的标准。令人极感震惊的是，在一种原材料短缺的情形中，虽说没有人发布命令，也甚少有人知道个中原因，但是无以计数的人他们的身份五花八门，即使用数个月的时间也无法调查清楚——却都能够用一种更为节约的方式去使用这种原材料或者用这种原材料制成的产品。这就是说，他们会采取正确的行动。当然，在一个瞬息万变的世界里，并不是所有的人都能够把自己的活动调适到一个极其完美的程度的，因此他们的利润率只能始终保持在相同的甚或“常规”的水平上；即使如此，这种情形仍足以构成一项奇迹。
我故意使用“奇迹”（marvel）这个词，目的就是为了使读者能够克服人们在理所当然地看待价格机制之运作时常常带有的那种洋洋自得的心理。我相信，如果这种价格机制是人类刻意设计的产物，又如果受价格变化之引导的人们懂得他们的决策有着远远超出其即时性目的的重大意义，那么这种价格机制早就应当被赞誉为人之心智所达致的最伟大的成就之一了。然而颇为遗憾的是：一方面，价格机制并不是人之设计的产物；而另一方面，那些受价格机制指导的人通常也不知道自己为什么要如此行事。但是需要强调指出的是，那些嚷嚷着主张“刻意指导”的人——以及那些根本就不相信某种未经设计（甚至是在人们并不理解的情况下）便自发形成的东西能够解决我们经由一种刻意的方式都无力加以解决的问题的人——应当牢记：这里的问题恰恰在于如何才能把我们运用资源的范围扩展到任何个人心智所能控制的范围以外；因此，这也是一个如何才能否弃刻意控制之必要性以及如何才能提供激励以使个人在不需要任何人告诉他们该做什么事情的情况下去做可欲之事的问题。
我们在这里碰到的问题绝不是经济学所特有的问题，而是与几乎所有真正的社会现象､与语言以及与我们的大多数文化遗产都有紧密关系的问题；据此我们可以说，这个问题实际上构成了整个社会科学的核心理论问题。正如艾尔费雷德·怀特海在讨论另一个问题时所指出的，“尽管所有的格言书和大人物在演说时都反复强调说，我们应当养成对我们正在做的事情进行思考的习惯，但这却是一个根深蒂固且大错特错的陈词滥调。因为事实表明：文明的进步，乃是通过增加我们毋需考虑便能运作的重大活动的数量而得以实现的。”这种情形在社会领域中有着极为重要的意义。的确，我们会不断地使用一些我们并不理解其含义的公式､符号和规则，而且通过对它们的运用，我们还能够得到我们作为个人并不拥有的那种知识的帮助。在这个方面，我们已然发展起了一些惯例和制度，然而我们这种成就所依凭的则是那些在其各自领域中被证明为成功的､进而又成为我们文明之基石的习惯和制度。
的确，人类最初是在并不理解的情况下偶然发现了某些惯例和制度的，只是在后来才慢慢学会了如何运用它们，尽管人类直到今天还远远没有学会如何充分运用它们；需要指出的是，价格体系只是这些惯例和制度当中的一种而已。正是通过这种价格体系的作用，劳动分工（a division of labor）和以分立知识（divided knowledge）为基础的协调运用资源的做法才有了可能。那些喜欢嘲弄和讥讽任何上述主张的人，通常都是通过一种暗讽的说法来歪曲这种主张的。他们指出，这种主张竟然宣称说，这种最适合于现代文明的价格体系乃是通过某种奇迹而自发形成的。然而值得我们注意的是，上述主张实际上是极有道理的：人类之所以能够发展起我们的文明赖以为基础的劳动分工制度，实是因为人类碰巧发现了一种使劳动分工成为可能的方法。如果人类不曾发现这种方法。那么他们仍可能会发展起某种完全不同的其他文明类型，就像某种白蚁“国”一样，或者某种完全无法想象的其他文明类型。对此我们只能够说，迄今为止还没有人成功地设计出一种替代性体系——在这种替代性体系中，现行的价格体系所具有的某些特征（亦即对于那些最激烈抨击这种价格体系的人来说也是极为可贵的那些特征）仍能够得到维续：比如说，它已然达到的能够使个人选择自己的事业并因此而可以自由地使用他自己的知识和技艺的程度。
七
在很大程度上讲，有关价格体系对于一个复杂社会中的任何理性计算来说是否是必不可少的争论，现在已经不再是持有不同政治观点的两大阵营之间的那种争论了；从许多方面来看，这是一件幸事。一如我们所知，早在25年以前，当冯·米塞斯最初提出没有价格体系我们就不可能维续一个以当下既存的极其广泛的劳动分工为基础的社会这个命题的时候，他的这个命题便遭到了一阵阵嘲弄和讥讽。今天，一些人仍然觉得很难接受这个命题，但是在很大程度上讲，这方面的困难已不再是政治上的问题了；当然，这种情形也营造出了一种更有助于人们进行理性讨论的氛围。当我们看到托洛斯基说“没有市场关系，经济核算乃是不可想象的”时候，当奥斯卡·兰格（Oscar Lange）教授允诺在未来的中央计划局大理石大厅中为冯·米塞斯教授建一尊雕像的时候，又当阿巴·勒纳（Abba P. Lemer）教授重新发现亚当·斯密（Adam Smith）并强调价格体系的基本作用乃在于激励个人在追求自身利益的同时去做一些符合一般利益的事情的时候，他们之间的分歧也就确实不能再被归于政治偏见了。显而易见，当下的分歧乃是因为纯粹知识上的分歧所致，尤其是因为方法论上的分歧所致。
我记得，约瑟夫·熊彼特在其晚近发表的《资本主义､社会主义和民主》（Capitalism, Socialism, and Democracy）书中有这样一段文字，它清楚地说明了这些方法论分歧当中的一种分歧。在那些根据实证主义某一分支观点研究经济现象的经济学家当中，熊彼特可以说是佼佼者。在他看来，经济现象似乎是客观给定的彼此直接影响的商品量，而且几乎是在不受人之心智任何干预的情况下发生这种彼此影响的。唯有根据这个理论背景，我才能够对他给出的下述令我惊讶不已的论点做出说明。熊彼特教授认为，经济理论中有一项基本主张，即“消费者在估价（需求）消费品的时候，事实上也是在对用于生产这些商品的生产资料进行估价”。他在此基础上更是宣称，在不存在生产要素市场的情况下，理论家仍有可能根据上述基本主张进行理性的计算。①
如果我们从字面上来理解熊彼特的这个说法，那么我们可以说，他的这个说法根本就不是真实的，因为消费者从来就不做这样的事情。熊彼特教授所说的“事实上”，大概是指对生产要素的估价隐含于消费者对消费品的估价之中，或者是指前者是后者的必然结果；但是，即使如此，这种说法也是不正确的。一如我们所知，隐含关系乃是一种逻辑关系，而只有当所有相关的事情都同时为某个人所知道的时候，他才能够有意义地宣称这种逻辑关系。然而显见不争的是，生产要素的价值不仅取决于对消费品的估价，而且还要取决于各种生产要素的供应情况。只有当所有这些事实都同时为一个人所知道的时候，他才能够以逻辑的方式从他所知道的这些特定事实中得出相关的结论。但是，实践过程中之所以会出现问题，恰恰就是因为：第一，这些事实绝不是同时为某个人所知道的；第二，在解决这种问题的过程当中，人们只能运用那种由众多个人分散掌握的知识。
如果某个人知道所有的事实（正如我们假设所有的事实对于作为观察者的经济学家来说都是给定的那样），那么他自己就可以确定某种解决方法。但是，即使我们能够证明这一点，我们在上面所说的那个问题仍未得到任何解决。因此，我们必须证明，一项解决方法究竟是如何通过每个只掌握部分知识的人之间的互动而得以产生的。假设一个人可以拥有所有这种知识——正如假设所有这种知识对于作为解释者的经济学家来说都是给定的一般，无异于认定这个问题是不存在的，而且也无异于对现实世界中所存在的所有意义重大的事情的无视。
一个持有熊彼特教授之立场的经济学家，显然会因为“数据”或“基据”这个术语的含混不清而跌入它为冒失鬼所设定的陷阱之中；这种情况很难被解释成一种简单的失误。我认为，这种情况毋宁说明了这样一个道理，即那种习惯于无视我们必须直面的那些基本现象的认识进路确实存在着某种根本性的错误，因为第一，人的知识必定是不完全的；第二，人们因此需要有一种不断交流知识和获得知识的途径。据此我们可以说，任何一种以人的知识与特定情势中的客观事实相一致的假设作为实际出发点的认识进路，诸如许多采用联立方程式的数理经济学家所持的那种认识进路，都会把我们的主要任务所旨在解释的那种问题排斥在考虑之外。我绝不否认，在我们的体系中，均衡分析可以起到一种有益的作用。但是需要强调指出的是，当这种均衡分析已然致使一些极为重要的思想家误以为它所描述的情形与实际问题的解决有着直接相关性的时候，亦就是我们必须提请人们牢记这样两个道理的时候了：第一，均衡分析根本就不探讨社会过程的问题；第二，均衡分析只是我们着手研究主要问题之前的一种有助益的准备工作而已。
参考文献
① J. Schumpeter, Capitalism, Socialism, and Democracy (New York; Harper, 1942), p. 175。我认为，熊彼特教授也是帕累托和巴罗内“解决了”社会主义计算问题这一神话的原创者。其实他们和其他许多人所做的，只是陈述了资源的合理配置必须满足的条件，并指出这些条件与竞争性市场的均衡条件基本相同。这与知道如何在实践中找到满足这些条件的资源分配是完全不同的。帕累托本人（巴罗内几乎从他那里得到了他要说的一切），非但没有声称自己已经解决了这个实际问题，事实上，他明确否认没有市场的帮助就可以解决这个问题。参见他的《Manuel d’économie pure》（第二版，1927年），第233-34页。我在《Economica, New Series》的第八卷，第26期（1940年5月），第125页的《Socialist Calculation: The Competitive ‘Solution》一文的开头引用了相关段落的英译。
附：原文
The Use of Knowledge in Society
—By Friedrich A. Hayek
I
What is the problem we wish to solve when we try to construct a rational economic order?
On certain familiar assumptions the answer is simple enough. If we possess all the relevant information, if we can start out from a given system of preferences, and if we command complete knowledge of available means, the problem which remains is purely one of logic. That is, the answer to the question of what is the best use of the available means is implicit in our assumptions. The conditions which the solution of this optimum problem must satisfy have been fully worked out and can be stated best in mathematical form: put at their briefest, they are that the marginal rates of substitution between any two commodities or factors must be the same in all their different uses.
This, however, is emphatically not the economic problem which society faces. And the economic calculus which we have developed to solve this logical problem, though an important step toward the solution of the economic problem of society, does not yet provide an answer to it. The reason for this is that the “data” from which the economic calculus starts are never for the whole society “given” to a single mind which could work out the implications and can never be so given.
The peculiar character of the problem of a rational economic order is determined precisely by the fact that the knowledge of the circumstances of which we must make use never exists in concentrated or integrated form but solely as the dispersed bits of incomplete and frequently contradictory knowledge which all the separate individuals possess. The economic problem of society is thus not merely a problem of how to allocate “given” resources—if “given” is taken to mean given to a single mind which deliberately solves the problem set by these “data.” It is rather a problem of how to secure the best use of resources known to any of the members of society, for ends whose relative importance only these individuals know. Or, to put it briefly, it is a problem of the utilization of knowledge which is not given to anyone in its totality.
This character of the fundamental problem has, I am afraid, been obscured rather than illuminated by many of the recent refinements of economic theory, particularly by many of the uses made of mathematics. Though the problem with which I want primarily to deal in this paper is the problem of a rational economic organization, I shall in its course be led again and again to point to its close connections with certain methodological questions. Many of the points I wish to make are indeed conclusions toward which diverse paths of reasoning have unexpectedly converged. But, as I now see these problems, this is no accident. It seems to me that many of the current disputes with regard to both economic theory and economic policy have their common origin in a misconception about the nature of the economic problem of society. This misconception in turn is due to an erroneous transfer to social phenomena of the habits of thought we have developed in dealing with the phenomena of nature.
II
In ordinary language we describe by the word “planning” the complex of interrelated decisions about the allocation of our available resources. All economic activity is in this sense planning; and in any society in which many people collaborate, this planning, whoever does it, will in some measure have to be based on knowledge which, in the first instance, is not given to the planner but to somebody else, which somehow will have to be conveyed to the planner. The various ways in which the knowledge on which people base their plans is communicated to them is the crucial problem for any theory explaining the economic process, and the problem of what is the best way of utilizing knowledge initially dispersed among all the people is at least one of the main problems of economic policy—or of designing an efficient economic system.
The answer to this question is closely connected with that other question which arises here, that of who is to do the planning. It is about this question that all the dispute about “economic planning” centers. This is not a dispute about whether planning is to be done or not. It is a dispute as to whether planning is to be done centrally, by one authority for the whole economic system, or is to be divided among many individuals. Planning in the specific sense in which the term is used in contemporary controversy necessarily means central planning—direction of the whole economic system according to one unified plan. Competition, on the other hand, means decentralized planning by many separate persons. The halfway house between the two, about which many people talk but which few like when they see it, is the delegation of planning to organized industries, or, in other words, monopoly.
Which of these systems is likely to be more efficient depends mainly on the question under which of them we can expect that fuller use will be made of the existing knowledge. And this, in turn, depends on whether we are more likely to succeed in putting at the disposal of a single central authority all the knowledge which ought to be used but which is initially dispersed among many different individuals, or in conveying to the individuals such additional knowledge as they need in order to enable them to fit their plans with those of others.
III
It will at once be evident that on this point the position will be different with respect to different kinds of knowledge; and the answer to our question will therefore largely turn on the relative importance of the different kinds of knowledge; those more likely to be at the disposal of particular individuals and those which we should with greater confidence expect to find in the possession of an authority made up of suitably chosen experts. If it is today so widely assumed that the latter will be in a better position, this is because one kind of knowledge, namely, scientific knowledge, occupies now so prominent a place in public imagination that we tend to forget that it is not the only kind that is relevant. It may be admitted that, as far as scientific knowledge is concerned, a body of suitably chosen experts may be in the best position to command all the best knowledge available—though this is of course merely shifting the difficulty to the problem of selecting the experts. What I wish to point out is that, even assuming that this problem can be readily solved, it is only a small part of the wider problem.
Today it is almost heresy to suggest that scientific knowledge is not the sum of all knowledge. But a little reflection will show that there is beyond question a body of very important but unorganized knowledge which cannot possibly be called scientific in the sense of knowledge of general rules: the knowledge of the particular circumstances of time and place. It is with respect to this that practically every individual has some advantage over all others because he possesses unique information of which beneficial use might be made, but of which use can be made only if the decisions depending on it are left to him or are made with his active coöperation. We need to remember only how much we have to learn in any occupation after we have completed our theoretical training, how big a part of our working life we spend learning particular jobs, and how valuable an asset in all walks of life is knowledge of people, of local conditions, and of special circumstances. To know of and put to use a machine not fully employed, or somebody’s skill which could be better utilized, or to be aware of a surplus stock which can be drawn upon during an interruption of supplies, is socially quite as useful as the knowledge of better alternative techniques. And the shipper who earns his living from using otherwise empty or half-filled journeys of tramp-steamers, or the estate agent whose whole knowledge is almost exclusively one of temporary opportunities, or the arbitrageur who gains from local differences of commodity prices, are all performing eminently useful functions based on special knowledge of circumstances of the fleeting moment not known to others.
It is a curious fact that this sort of knowledge should today be generally regarded with a kind of contempt and that anyone who by such knowledge gains an advantage over somebody better equipped with theoretical or technical knowledge is thought to have acted almost disreputably. To gain an advantage from better knowledge of facilities of communication or transport is sometimes regarded as almost dishonest, although it is quite as important that society make use of the best opportunities in this respect as in using the latest scientific discoveries. This prejudice has in a considerable measure affected the attitude toward commerce in general compared with that toward production. Even economists who regard themselves as definitely immune to the crude materialist fallacies of the past constantly commit the same mistake where activities directed toward the acquisition of such practical knowledge are concerned—apparently because in their scheme of things all such knowledge is supposed to be “given.” The common idea now seems to be that all such knowledge should as a matter of course be readily at the command of everybody, and the reproach of irrationality leveled against the existing economic order is frequently based on the fact that it is not so available. This view disregards the fact that the method by which such knowledge can be made as widely available as possible is precisely the problem to which we have to find an answer.
IV
If it is fashionable today to minimize the importance of the knowledge of the particular circumstances of time and place, this is closely connected with the smaller importance which is now attached to change as such. Indeed, there are few points on which the assumptions made (usually only implicitly) by the “planners” differ from those of their opponents as much as with regard to the significance and frequency of changes which will make substantial alterations of production plans necessary. Of course, if detailed economic plans could be laid down for fairly long periods in advance and then closely adhered to, so that no further economic decisions of importance would be required, the task of drawing up a comprehensive plan governing all economic activity would be much less formidable.
It is, perhaps, worth stressing that economic problems arise always and only in consequence of change. So long as things continue as before, or at least as they were expected to, there arise no new problems requiring a decision, no need to form a new plan. The belief that changes, or at least day-to-day adjustments, have become less important in modern times implies the contention that economic problems also have become less important. This belief in the decreasing importance of change is, for that reason, usually held by the same people who argue that the importance of economic considerations has been driven into the background by the growing importance of technological knowledge.
Is it true that, with the elaborate apparatus of modern production, economic decisions are required only at long intervals, as when a new factory is to be erected or a new process to be introduced? Is it true that, once a plant has been built, the rest is all more or less mechanical, determined by the character of the plant, and leaving little to be changed in adapting to the ever-changing circumstances of the moment?
The fairly widespread belief in the affirmative is not, as far as I can ascertain, borne out by the practical experience of the businessman. In a competitive industry at any rate—and such an industry alone can serve as a test—the task of keeping cost from rising requires constant struggle, absorbing a great part of the energy of the manager. How easy it is for an inefficient manager to dissipate the differentials on which profitability rests, and that it is possible, with the same technical facilities, to produce with a great variety of costs, are among the commonplaces of business experience which do not seem to be equally familiar in the study of the economist. The very strength of the desire, constantly voiced by producers and engineers, to be allowed to proceed untrammeled by considerations of money costs, is eloquent testimony to the extent to which these factors enter into their daily work.
One reason why economists are increasingly apt to forget about the constant small changes which make up the whole economic picture is probably their growing preoccupation with statistical aggregates, which show a very much greater stability than the movements of the detail. The comparative stability of the aggregates cannot, however, be accounted for—as the statisticians occasionally seem to be inclined to do—by the “law of large numbers” or the mutual compensation of random changes. The number of elements with which we have to deal is not large enough for such accidental forces to produce stability. The continuous flow of goods and services is maintained by constant deliberate adjustments, by new dispositions made every day in the light of circumstances not known the day before, by B stepping in at once when A fails to deliver. Even the large and highly mechanized plant keeps going largely because of an environment upon which it can draw for all sorts of unexpected needs; tiles for its roof, stationery for its forms, and all the thousand and one kinds of equipment in which it cannot be self-contained and which the plans for the operation of the plant require to be readily available in the market.
This is, perhaps, also the point where I should briefly mention the fact that the sort of knowledge with which I have been concerned is knowledge of the kind which by its nature cannot enter into statistics and therefore cannot be conveyed to any central authority in statistical form. The statistics which such a central authority would have to use would have to be arrived at precisely by abstracting from minor differences between the things, by lumping together, as resources of one kind, items which differ as regards location, quality, and other particulars, in a way which may be very significant for the specific decision. It follows from this that central planning based on statistical information by its nature cannot take direct account of these circumstances of time and place and that the central planner will have to find some way or other in which the decisions depending on them can be left to the “man on the spot.”
V
If we can agree that the economic problem of society is mainly one of rapid adaptation to changes in the particular circumstances of time and place, it would seem to follow that the ultimate decisions must be left to the people who are familiar with these circumstances, who know directly of the relevant changes and of the resources immediately available to meet them. We cannot expect that this problem will be solved by first communicating all this knowledge to a central board which, after integrating all knowledge, issues its orders. We must solve it by some form of decentralization. But this answers only part of our problem. We need decentralization because only thus can we insure that the knowledge of the particular circumstances of time and place will be promptly used. But the “man on the spot” cannot decide solely on the basis of his limited but intimate knowledge of the facts of his immediate surroundings. There still remains the problem of communicating to him such further information as he needs to fit his decisions into the whole pattern of changes of the larger economic system.
How much knowledge does he need to do so successfully? Which of the events which happen beyond the horizon of his immediate knowledge are of relevance to his immediate decision, and how much of them need he know?
There is hardly anything that happens anywhere in the world that might not have an effect on the decision he ought to make. But he need not know of these events as such, nor of all their effects. It does not matter for him why at the particular moment more screws of one size than of another are wanted,why paper bags are more readily available than canvas bags, or why skilled labor, or particular machine tools, have for the moment become more difficult to obtain. All that is significant for him is how much more or less difficult to procure they have become compared with other things with which he is also concerned, or how much more or less urgently wanted are the alternative things he produces or uses. It is always a question of the relative importance of the particular things with which he is concerned, and the causes which alter their relative importance are of no interest to him beyond the effect on those concrete things of his own environment.
It is in this connection that what I have called the “economic calculus” proper helps us, at least by analogy, to see how this problem can be solved, and in fact is being solved, by the price system. Even the single controlling mind, in possession of all the data for some small, self-contained economic system, would not—every time some small adjustment in the allocation of resources had to be made—go explicitly through all the relations between ends and means which might possibly be affected. It is indeed the great contribution of the pure logic of choice that it has demonstrated conclusively that even such a single mind could solve this kind of problem only by constructing and constantly using rates of equivalence (or “values,” or “marginal rates of substitution”),i.e., by attaching to each kind of scarce resource a numerical index which cannot be derived from any property possessed by that particular thing, but which reflects, or in which is condensed, its significance in view of the whole means-end structure. In any small change he will have to consider only these quantitative indices (or “values”) in which all the relevant information is concentrated; and, by adjusting the quantities one by one, he can appropriately rearrange his dispositions without having to solve the whole puzzle ab initio or without needing at any stage to survey it at once in all its ramifications.
Fundamentally, in a system in which the knowledge of the relevant facts is dispersed among many people, prices can act to coördinate the separate actions of different people in the same way as subjective values help the individual to coördinate the parts of his plan. It is worth contemplating for a moment a very simple and commonplace instance of the action of the price system to see what precisely it accomplishes. Assume that somewhere in the world a new opportunity for the use of some raw material, say, tin, has arisen, or that one of the sources of supply of tin has been eliminated. It does not matter for our purpose—and it is very significant that it does not matter—which of these two causes has made tin more scarce. All that the users of tin need to know is that some of the tin they used to consume is now more profitably employed elsewhere and that, in consequence, they must economize tin. There is no need for the great majority of them even to know where the more urgent need has arisen, or in favor of what other needs they ought to husband the supply. If only some of them know directly of the new demand, and switch resources over to it, and if the people who are aware of the new gap thus created in turn fill it from still other sources, the effect will rapidly spread throughout the whole economic system and influence not only all the uses of tin but also those of its substitutes and the substitutes of these substitutes, the supply of all the things made of tin, and their substitutes, and so on; and all this without the great majority of those instrumental in bringing about these substitutions knowing anything at all about the original cause of these changes. The whole acts as one market, not because any of its members survey the whole field, but because their limited individual fields of vision sufficiently overlap so that through many intermediaries the relevant information is communicated to all. The mere fact that there is one price for any commodity—or rather that local prices are connected in a manner determined by the cost of transport, etc.—brings about the solution which (it is just conceptually possible) might have been arrived at by one single mind possessing all the information which is in fact dispersed among all the people involved in the process.
VI
We must look at the price system as such a mechanism for communicating information if we want to understand its real function—a function which, of course, it fulfils less perfectly as prices grow more rigid. (Even when quoted prices have become quite rigid, however, the forces which would operate through changes in price still operate to a considerable extent through changes in the other terms of the contract.) The most significant fact about this system is the economy of knowledge with which it operates, or how little the individual participants need to know in order to be able to take the right action. In abbreviated form, by a kind of symbol, only the most essential information is passed on and passed on only to those concerned. It is more than a metaphor to describe the price system as a kind of machinery for registering change, or a system of telecommunications which enables individual producers to watch merely the movement of a few pointers, as an engineer might watch the hands of a few dials, in order to adjust their activities to changes of which they may never know more than is reflected in the price movement.
Of course, these adjustments are probably never “perfect” in the sense in which the economist conceives of them in his equilibrium analysis. But I fear that our theoretical habits of approaching the problem with the assumption of more or less perfect knowledge on the part of almost everyone has made us somewhat blind to the true function of the price mechanism and led us to apply rather misleading standards in judging its efficiency. The marvel is that in a case like that of a scarcity of one raw material, without an order being issued, without more than perhaps a handful of people knowing the cause, tens of thousands of people whose identity could not be ascertained by months of investigation, are made to use the material or its products more sparingly; i.e., they move in the right direction. This is enough of a marvel even if, in a constantly changing world, not all will hit it off so perfectly that their profit rates will always be maintained at the same constant or “normal” level.
I have deliberately used the word “marvel” to shock the reader out of the complacency with which we often take the working of this mechanism for granted. I am convinced that if it were the result of deliberate human design, and if the people guided by the price changes understood that their decisions have significance far beyond their immediate aim, this mechanism would have been acclaimed as one of the greatest triumphs of the human mind. Its misfortune is the double one that it is not the product of human design and that the people guided by it usually do not know why they are made to do what they do. But those who clamor for “conscious direction”—and who cannot believe that anything which has evolved without design (and even without our understanding it) should solve problems which we should not be able to solve consciously—should remember this: The problem is precisely how to extend the span of our utilization of resources beyond the span of the control of any one mind; and therefore, how to dispense with the need of conscious control, and how to provide inducements which will make the individuals do the desirable things without anyone having to tell them what to do.
The problem which we meet here is by no means peculiar to economics but arises in connection with nearly all truly social phenomena, with language and with most of our cultural inheritance, and constitutes really the central theoretical problem of all social science. As Alfred Whitehead has said in another connection, “It is a profoundly erroneous truism, repeated by all copy-books and by eminent people when they are making speeches, that we should cultivate the habit of thinking what we are doing. The precise opposite is the case. Civilization advances by extending the number of important operations which we can perform without thinking about them.”
This is of profound significance in the social field. We make constant use of formulas, symbols, and rules whose meaning we do not understand and through the use of which we avail ourselves of the assistance of knowledge which individually we do not possess. We have developed these practices and institutions by building upon habits and institutions which have proved successful in their own sphere and which have in turn become the foundation of the civilization we have built up.
The price system is just one of those formations which man has learned to use (though he is still very far from having learned to make the best use of it) after he had stumbled upon it without understanding it. Through it not only a division of labor but also a coördinated utilization of resources based on an equally divided knowledge has become possible. The people who like to deride any suggestion that this may be so usually distort the argument by insinuating that it asserts that by some miracle just that sort of system has spontaneously grown up which is best suited to modern civilization. It is the other way round: man has been able to develop that division of labor on which our civilization is based because he happened to stumble upon a method which made it possible. Had he not done so, he might still have developed some other, altogether different, type of civilization, something like the “state” of the termite ants, or some other altogether unimaginable type. All that we can say is that nobody has yet succeeded in designing an alternative system in which certain features of the existing one can be preserved which are dear even to those who most violently assail it—such as particularly the extent to which the individual can choose his pursuits and consequently freely use his own knowledge and skill.
VII
It is in many ways fortunate that the dispute about the indispensability of the price system for any rational calculation in a complex society is now no longer conducted entirely between camps holding different political views. The thesis that without the price system we could not preserve a society based on such extensive division of labor as ours was greeted with a howl of derision when it was first advanced by von Mises twenty-five years ago. Today the difficulties which some still find in accepting it are no longer mainly political, and this makes for an atmosphere much more conducive to reasonable discussion. When we find Leon Trotsky arguing that “economic accounting is unthinkable without market relations”; when Professor Oscar Lange promises Professor von Mises a statue in the marble halls of the future Central Planning Board; and when Professor Abba P. Lerner rediscovers Adam Smith and emphasizes that the essential utility of the price system consists in inducing the individual, while seeking his own interest, to do what is in the general interest, the differences can indeed no longer be ascribed to political prejudice. The remaining dissent seems clearly to be due to purely intellectual, and more particularly methodological, differences.
A recent statement by Professor Joseph Schumpeter in his Capitalism, Socialism, and Democracy provides a clear illustration of one of the methodological differences which I have in mind. Its author is pre-eminent among those economists who approach economic phenomena in the light of a certain branch of positivism. To him these phenomena accordingly appear as objectively given quantities of commodities impinging directly upon each other, almost, it would seem, without any intervention of human minds. Only against this background can I account for the following (to me startling) pronouncement. Professor Schumpeter argues that the possibility of a rational calculation in the absence of markets for the factors of production follows for the theorist “from the elementary proposition that consumers in evaluating (‘demanding’) consumers’ goods ipso facto also evaluate the means of production which enter into the production of these goods."①
Taken literally, this statement is simply untrue. The consumers do nothing of the kind. What Professor Schumpeter’s"ipso facto” presumably means is that the valuation of the factors of production is implied in, or follows necessarily from, the valuation of consumers’ goods. But this, too, is not correct. Implication is a logical relationship which can be meaningfully asserted only of propositions simultaneously present to one and the same mind. It is evident, however, that the values of the factors of production do not depend solely on the valuation of the consumers’ goods but also on the conditions of supply of the various factors of production. Only to a mind to which all these facts were simultaneously known would the answer necessarily follow from the facts given to it. The practical problem, however, arises precisely because these facts are never so given to a single mind, and because, in consequence, it is necessary that in the solution of the problem knowledge should be used that is dispersed among many people.
The problem is thus in no way solved if we can show that all the facts, if they were known to a single mind (as we hypothetically assume them to be given to the observing economist), would uniquely determine the solution; instead we must show how a solution is produced by the interactions of people each of whom possesses only partial knowledge. To assume all the knowledge to be given to a single mind in the same manner in which we assume it to be given to us as the explaining economists is to assume the problem away and to disregard everything that is important and significant in the real world.
That an economist of Professor Schumpeter’s standing should thus have fallen into a trap which the ambiguity of the term “datum” sets to the unwary can hardly be explained as a simple error. It suggests rather that there is something fundamentally wrong with an approach which habitually disregards an essential part of the phenomena with which we have to deal: the unavoidable imperfection of man’s knowledge and the consequent need for a process by which knowledge is constantly communicated and acquired. Any approach, such as that of much of mathematical economics with its simultaneous equations, which in effect starts from the assumption that people’s knowledge corresponds with the objective facts of the situation, systematically leaves out what is our main task to explain. I am far from denying that in our system equilibrium analysis has a useful function to perform. But when it comes to the point where it misleads some of our leading thinkers into believing that the situation which it describes has direct relevance to the solution of practical problems, it is high time that we remember that it does not deal with the social process at all and that it is no more than a useful preliminary to the study of the main problem.
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Reference
① J. Schumpeter, Capitalism, Socialism, and Democracy (New York; Harper, 1942), p. 175. Professor Schumpeter is, I believe, also the original author of the myth that Pareto and Barone have "solved" the problem of socialist calculation. What they, and many others, did was merely to state the conditions which a rational allocation of resources would have to satisfy and to point out that these were essentially the same as the conditions of equilibrium of a competitive market. This is something altogether different from knowing how the allocation of resources satisfying these conditions can be found in practice. Pareto himself (from whom Barone has taken practically everything he has to say), far from claiming to have solved the practical problem, in fact explicitly denies that it can be solved without the help of the market. See his Manuel d'économie pure (2d ed., 1927), pp. 233-34. The relevant passage is quoted in an English translation at the beginning of my article on "Socialist Calculation: The Competitive 'Solution,' " in Economica, New Series, Vol. VIII, No. 26 (May, 1940), p. 125.