謹(jǐn)記經(jīng)濟學(xué)的“自我實現(xiàn)屬性”
紐約大學(xué)斯特恩商學(xué)院(Stern School of Business)經(jīng)濟學(xué)家約翰•J•霍頓(John J Horton)最近發(fā)表的一篇博客文章說，使用亞馬遜(Amazon)的土耳其機器人(Mechanical Turk)服務(wù)的潛在雇主的開價是每小時1.38美元。這一薪資水平不止是低，其數(shù)字本身也很奇怪。為什么是1.38美元?霍頓猜測這一數(shù)字來自7年前他聯(lián)名發(fā)表的一篇論文，該論文報告稱，在土耳其機器人開展的試驗中，1.38美元是保留工資的中位數(shù)。所謂保留工資，是指低于該水平個人就不會接受相關(guān)工作的工資水平。
He suggests this is an example of “performativity” in economics. This term originates in linguistic philosophy, where it refers to statements whose very utterance is the action referred to: “I name this ship the QE2” or “I promise I’ll do the washing up.”
他指出這是經(jīng)濟學(xué)中“操演性”(performativity)的一個例子。“操演性”這個名詞源自語言哲學(xué)，是指那種說出來本身就完成了所指動作的陳述：“我將這條船命名為QE2”，或者“我發(fā)誓我會清洗的”。
Some sociologists have applied the concept to economic theory. One of the most notable examples is the Black-Scholes-Merton model of option pricing. Professor Donald Mackenzie, of University of Edinburgh, argued that before the publication of the model, no market for options was possible as nobody was sure how to price these instruments. Once there was an agreed pricing model, the market sprang into existence.
部分社會學(xué)者將這一概念用到了經(jīng)濟學(xué)理論中。其中一個最引人注目的例子就是有關(guān)期權(quán)定價的布萊克-斯科爾斯-默頓(Black-Scholes-Merton)模型。愛丁堡大學(xué)(University of Edinburgh)教授唐納德•麥肯茲(Donald MacKenzie)曾指出，在該模型發(fā)表之前，由于沒人能確定如何為期權(quán)定價，期權(quán)市場根本不可能存在。一旦存在了人人認可的定價模型，市場就突然存在了。
It only takes a bit of reflection to see that a lot of economics concerns self-fulfilling (or self-averting) phenomena. An economy can go into recession when enough people think it will, for instance. But while accepting that expectations are important, many economists would regard the idea that the way they think about the world changes the world as fanciful. They see themselves rather as careful observers of empirical facts.
只需要略微思考一下，就可以發(fā)現(xiàn)許多經(jīng)濟學(xué)涉及自我實現(xiàn)(或自我避免)的現(xiàn)象。比如，當(dāng)足夠多的人認為一個經(jīng)濟體會陷入衰退時，這個經(jīng)濟體就可能陷入衰退。不過，盡管許多經(jīng)濟學(xué)家承認預(yù)期很重要，但對于經(jīng)濟學(xué)家對世界的看法會改變世界這種想法，他們卻認為是一種幻想。他們寧愿將自己視為對經(jīng)驗事實的小心觀察者。
I have never been so sure. And, as it happened, Prof Horton’s post about an old paper affecting wages was not the only recent example of financial performativity. The other was the horrifying attack on the Borussia Dortmund bus, seemingly carried out to make a profit on put options on the football club’s share price.
對于這種現(xiàn)象，我從未像現(xiàn)在這樣確信，而且，事實上，霍頓教授有關(guān)舊論文影響薪資水平的帖子，并不是近期金融操演性的唯一例子。另一個例子是對多特蒙德俱樂部(Borussia Dortmund)大巴的可怕襲擊，其目的似乎是為了利用對該足球俱樂部股價的看跌期權(quán)盈利。
Attempts to rig financial market prices long predate economics. Yet, though real world effects are often a byproduct of financial trades, there is something highly disturbing about this attempt to change reality to bring about a particular market outcome, rather than attempting manipulation by, say, spreading rumours.
在經(jīng)濟學(xué)出現(xiàn)很久以前，就有人企圖操縱金融市場價格。然而，盡管對真實世界的影響往往是金融交易的副產(chǎn)品，但這種試圖改變現(xiàn)實來實現(xiàn)特定市場結(jié)果、而不是試圖通過比如說擴散謠言來操縱市場的做法，也非常令人擔(dān)憂。
All the blame lies with the criminal, not with economics. The moral opprobrium in the MTurk case lies with the employer offering a pittance. But it is important for economists to understand that they are players in the world they analyse, uncomfortable as it makes them to go down this self-referential rabbit hole. In fact, the very conceptual framework — that there is a self-contained domain called “the economy’” that is measured by statistics such as gross domestic product and the unemployment rate — affects behaviour in ways that bring about exactly what is described. After all, we do have an economy.
所有譴責(zé)都落到了犯罪分子身上，沒有落到經(jīng)濟學(xué)身上。土耳其機器人一例中的道德譴責(zé)落到了開價低廉的雇主身上。然而，對經(jīng)濟學(xué)家來說重要的是，要明白他們是其所分析世界的參與者——盡管這會讓他們因陷入自我引述的循環(huán)而很不舒服。事實上，那種認為存在一個由國內(nèi)生產(chǎn)總值(GDP)和失業(yè)率等統(tǒng)計數(shù)字衡量的名為“經(jīng)濟體”的獨立世界的概念框架，恰恰通過影響人們的行為，催生了其所描述的東西。結(jié)果，我們就確實有了“經(jīng)濟體”這個東西。
However, there could have been alternative realities. Suppose instead of the GDP statistics defining the economy in terms of the market value of specified activities during certain periods there had been an alternative conceptual framework based on measuring the value of assets (including natural assets) in terms of how much it would cost to replace or restore them. There would have been less measured GDP growth and we would have a cleaner and greener society.
然而，另外一種現(xiàn)實原本也可能是存在的。想象一下，不采用以特定時期特定活動的市場價值定義經(jīng)濟體的GDP統(tǒng)計，而采用一種替代性的概念框架，其基礎(chǔ)是以重置或恢復(fù)資產(chǎn)(包括自然資產(chǎn))的成本來衡量資產(chǎn)的價值。這種框架下統(tǒng)計出的GDP增速會低一些，我們會擁有更清潔、更環(huán)保的社會。
It is not obvious which is better for human welfare, but the outcome we have reflects the framework of economic statistics and their underpinning theory. Statistics can make some things invisible by omission: unpaid work in the home is one example; another — until recently — has been distribution in terms of households’ position on the income ladder or income distribution region of the country. households’ position on the income ladder or income distribution in different regions of the country.
至于哪一種方式對人類的福祉更有利，并不是顯而易見的。不過，我們所得到的結(jié)果，反映了經(jīng)濟統(tǒng)計的架構(gòu)、以及它們背后的支撐理論。統(tǒng)計可以通過省略的辦法隱匿某些事物：在家中完成的沒有酬勞的工作就是個例子;另一個直至最近都被忽略的例子，是家庭收入在收入階梯中的分布情況，或一國收入的地區(qū)分布情況。
Critics of economics also hone in on the central role markets play in the discipline, arguing that this emphasis has marketised more and more of society. Michael Sandel’s bestselling What Money Can’t Buy is an eloquent statement of this critique. The argument conflates the use of processes of exchange to attain certain outcomes — including the market design strand of economics, used for example in Al Roth’s kidney exchange — with specific models of the market, whether option pricing or the idea that companies maximise shareholder value, or the claim that executives need incentive pay. Alternative models would lead to different conclusions and realities.
經(jīng)濟學(xué)的批評者也把火力集中到了市場在經(jīng)濟學(xué)中的中心地位上，稱經(jīng)濟學(xué)對市場的這種強調(diào)把社會中越來越多的領(lǐng)域市場化了。邁克爾•桑德爾(Michael Sandel)的暢銷書《金錢無法買到的東西》(What Money Can’t Buy)就是這種批評的一份雄辯聲明。他們的論證，把通過交換過程實現(xiàn)特定結(jié)果(包括經(jīng)濟學(xué)中的市場設(shè)計理論，該理論運用的一個例子，是阿爾•羅斯(Al Roth)有關(guān)換腎的研究)，與特定的市場模型(不論是期權(quán)定價模型、企業(yè)最大化股東價值的理念、還是高管需要激勵性薪酬的說法)混為一談。而換用不同的模型，可能會導(dǎo)致不同的結(jié)論和現(xiàn)實。
Still, the popularity of the anti-market mood demonstrated in large votes in many countries for candidates who claim they will turn back the tide is something we economists need to note and respond to. An answer that consists only in saying, “We are right, but need to do a better job of educating the public,” will not wash. For a start, we need to become more reflective about what happens when we send our models and measurements out into the world.
不過，在許多國家中，聲稱會逆轉(zhuǎn)市場化潮流的候選人得到大量選票，這反映出反市場情緒的流行，這是我們經(jīng)濟學(xué)家需要注意和回應(yīng)的現(xiàn)象。只說一句“我們是對的，我們只是需要更好地教育公眾”，是不會令人信服的。作為開始，我們需要更充分考慮到把我們的模型或指標(biāo)向世界推廣時會發(fā)生什么。
Diane Coyle is a professor of economics at the University of Manchester
黛安娜•科伊爾(Diane Coyle)是曼徹斯特大學(xué)(University of Manchester)經(jīng)濟學(xué)教授
