Gracie's wonderland ­

Here records everything I do for my dream; whether tears or laughters, progress is what really matters ­

­

4 ­

­

   ­

[2009.07.18]What went wrong with economics [/B]經(jīng)濟學怎么了[/B][/B]­

­

And how the discipline should change to avoid the mistakes of the past ­

這個學科該如何改進以避免過去的錯誤­

What went wrong with economics經(jīng)濟學怎么了Jul 18th 2009­

­

OF ALL the economic bubbles that have been pricked, few have burst more spectacularly than the reputation of economics itself. A few years ago, the dismal science was being acclaimed as a way of explaining ever more forms of human behaviour, from drug-dealing to sumo-wrestling. Wall Street ransacked the best universities for game theorists and options modellers. And on the public stage, economists were seen as far more trustworthy than politicians. John McCain joked that Alan Greenspan, then chairman of the Federal Reserve, was so indispensable that if he died, the president should “prop him up and put a pair of dark glasses on him.” ­

在所有已破滅的經(jīng)濟泡沫中，其所對應經(jīng)濟學的名聲敗壞往往更引人注目,。若干年前,，乏味的科學被稱為是用來解釋更多人類行為模式——從毒品交易到相撲運動——的一種方法。華爾街在最好的大學中尋找經(jīng)濟游戲的理論家和經(jīng)濟抉擇的塑造者,。而公眾認為經(jīng)濟學家比政治家有更多價值,。約翰·麥凱恩(John McCain)曾拿那時候的美聯(lián)儲主席艾倫·格林斯潘（Alan Greenspan）開玩笑說，他是必不可少的,，如果他去世,，總統(tǒng)都應該“戴上黑墨鏡來為他抬棺材”。­

In the wake of the biggest economic calamity in 80 years that reputation has taken a beating. In the public mind an arrogant profession has been humbled. Though economists are still at the centre of the policy debate—think of Ben Bernanke or Larry Summers in America or Mervyn King in Britain—their pronouncements are viewed with more scepticism than before. The profession itself is suffering from guilt and rancour. In a recent lecture, Paul Krugman, winner of the Nobel prize in economics in 2008, argued that much of the past 30 years of macroeconomics was “spectacularly useless at best, and positively harmful at worst.” Barry Eichengreen, a prominent American economic historian, says the crisis has “cast into doubt much of what we thought we knew about economics.” ­

80年代,，隨著最大的經(jīng)濟災難的出現(xiàn),，經(jīng)濟學的聲望就已經(jīng)受到了抨擊。在公眾的思維中,，這個自傲的職業(yè)變得低劣,。雖然經(jīng)濟學家仍然在政策討論起關鍵作用——想想美國的本·伯南克（Ben Bernanke）和拉里·薩默斯（Larry Summers）或者英國的默文·金 （Mervyn King）——但相比以前,，他們的言論要遭到更多質疑。這個行業(yè)自身遭受著罪惡和仇恨的影響,。在近期的一次演講中,，2008年諾貝爾經(jīng)濟學獎得主保羅·克魯格曼（Paul Krugman）就說，宏觀經(jīng)濟學在過去30年的大多數(shù)時間里“最好情況下是極度無用,，最好情況下就是危害深重了,。”杰出的美國經(jīng)濟歷史學家巴里·埃肯格林（Barry Eichengreen）說,，這場危機使我們對經(jīng)濟學的認識遭受質疑,。“­

In its crudest form—the idea that economics as a whole is discredited—the current backlash has gone far too far. If ignorance allowed investors and politicians to exaggerate the virtues of economics, it now blinds them to its benefits. Economics is less a slavish creed than a prism through which to understand the world. It is a broad canon, stretching from theories to explain how prices are determined to how economies grow. Much of that body of knowledge has no link to the financial crisis and remains as useful as ever.  ­

最粗俗的觀點是，經(jīng)濟學總的來說是不值得信任的,，而現(xiàn)在,，對這種觀點的對抗性反應已經(jīng)在漸漸消失。如果是無知使得投資者和政治家夸大了經(jīng)濟學的優(yōu)點,，現(xiàn)在,，無知讓他們看不到經(jīng)濟學所帶來的好處。與其說經(jīng)濟學是應該盲從的教條,，還不如說它是我們用來理解世界的棱鏡,。經(jīng)濟學是一個大概的準則，它來源于理論,，用來解釋經(jīng)濟的發(fā)展情況是如何決定價格的,。經(jīng)濟學的大多數(shù)主體知識和金融危機沒有關聯(lián)，并依舊有用處,。­

And if economics as a broad discipline deserves a robust defence, so does the free-market paradigm. Too many people, especially in Europe, equate mistakes made by economists with a failure of economic liberalism. Their logic seems to be that if economists got things wrong, then politicians will do better. That is a false—and dangerous—conclusion.  ­

如果經(jīng)濟學作為一門廣博的學科值得我們堅定的維護,，自由市場體也一樣值得。很多人,，特別在歐洲,，把經(jīng)濟學家犯的錯誤等同于自由經(jīng)濟主義的一次失敗。似乎,，他們的邏輯是,，如果經(jīng)濟學家做錯了事，政治家就能做得更好,。這是一個錯誤的,，危險的結論。­

Rational fools ­

大愚若智­

These important caveats, however, should not obscure the fact that two central parts of the discipline—macroeconomics and financial economics—are now, rightly, being severely re-examined . There are three main critiques: that macro and financial economists helped cause the crisis, that they failed to spot it, and that they have no idea how to fix it. ­

但是,，以上重要的警告并能掩蓋這樣一個事實,，即這一學科中的兩個中心部分——宏觀經(jīng)濟學和金融經(jīng)濟學目前確實遭到嚴格的再審查。對宏觀經(jīng)濟學和金融經(jīng)濟學有以下三種指責：他們助成了經(jīng)濟危機,；他們沒能發(fā)現(xiàn)經(jīng)濟危機,；他們對經(jīng)濟危機不知所措,。­

The first charge is half right. Macroeconomists, especially within central banks, were too fixated on taming inflation and too cavalier about asset bubbles. Financial economists, meanwhile, formalised theories of the efficiency of markets, fuelling the notion that markets would regulate themselves and financial innovation was always beneficial. Wall Street’s most esoteric instruments were built on these ideas.  第一種指責說對了一半。宏觀經(jīng)濟學,，特別是在中央銀行,，過度依戀于控制通貨膨脹而忽視了資產泡沫。于此同時,，金融經(jīng)濟學家把市場效率的理論成為書面形式,，激發(fā)了市場會自我規(guī)范，金融改革總是能收益的觀念,。華爾街大多數(shù)令人費解的證券就是在這種觀念上發(fā)行的,。­

But economists were hardly naive believers in market efficiency. Financial academics have spent much of the past 30 years poking holes in the “efficient market hypothesis”. A recent ranking of academic economists was topped by Joseph Stiglitz and Andrei Shleifer, two prominent hole-pokers. A newly prominent field, behavioural economics, concentrates on the consequences of irrational actions.  ­

但經(jīng)濟學家并不是市場效率的天真信徒。金融學者把過去30年里的大部分時間用來駁斥“效率市場假設”,。最近的理論性經(jīng)濟學家排名中,，兩位杰出的駁斥者，約瑟夫·斯蒂格利茨（Joseph Stiglitz）和安德烈·施萊弗（Andrei Shleifer）排名榜首,。行為經(jīng)濟學作為一個新的杰出領域，專注于不合理經(jīng)濟行為的后果,。­

So there were caveats aplenty. But as insights from academia arrived in the rough and tumble of Wall Street, such delicacies were put aside. And absurd assumptions were added. No economic theory suggests you should value mortgage derivatives on the basis that house prices would always rise. Finance professors are not to blame for this, but they might have shouted more loudly that their insights were being misused. Instead many cheered the party along (often from within banks). Put that together with the complacency of the macroeconomists and there were too few voices shouting stop.  ­

警告如此多,。但是，當學術界的見解傳達到華爾街的激烈競爭中時,，這些金玉良言卻被冷落一旁,。而荒唐的假設卻被添加進來。沒有經(jīng)濟理論告訴你要以房價會一直上漲為基礎來衡量抵押衍生物的價值,。金融專家不應為此受到指責,，但在他們的觀點被曲解時，他們應該更大聲的喊出來,。相反,，很多專家卻一直鼓勵當事人（一般和銀行有關）。加上宏觀經(jīng)濟學家的自滿,，就很少有聲音呼吁停止了,。­

Blindsided and divided ­

井底之蛙­

The charge that most economists failed to see the crisis coming also has merit. To be sure, some warned of trouble. The likes of Robert Shiller of Yale, Nouriel Roubini of New York University and the team at the Bank for International Settlements are now famous for their prescience. But most were blindsided. And even worrywarts who felt something was amiss had no idea of how bad the consequences would be. ­

指責大多數(shù)經(jīng)濟學家沒有察覺危機的來臨也有好處。不可否認,，有些人為經(jīng)濟危機做出了警告,。比如耶魯（Yale）的羅伯特·希勒（Robert Shiller），紐約大學（New York University ）的努里爾魯比尼（Nouriel Roubini ）以及銀行里的國際清算團隊,，現(xiàn)在,，因為他們的先見之明，他們出名了,。但大多數(shù)人還是不知所措,。即使那些杞人憂天者也不知道經(jīng)濟危機的結果會有多壞,。­

That was partly to do with professional silos, which limited both the tools available and the imaginations of the practitioners. Few financial economists thought much about illiquidity or counterparty risk, for instance, because their standard models ignore it; and few worried about the effect on the overall economy of the markets for all asset classes seizing up simultaneously, since few believed that was possible.  ­

這和專業(yè)簡倉有部分聯(lián)系，因為專業(yè)簡倉制約了實用性的工具和實際工作者的想象力,。比如,，沒有金融經(jīng)濟學家考慮不動產或者交易對方的風險，因為他們的標準模式就忽視了這個,；沒有人擔心所有資產類同時停止運轉對市場經(jīng)濟影響,，因為沒有人相信這種情況會發(fā)生。­

Macroeconomists also had a blindspot: their standard models assumed that capital markets work perfectly. Their framework reflected an uneasy truce between the intellectual heirs of Keynes, who accept that economies can fall short of their potential, and purists who hold that supply must always equal demand. The models that epitomise this synthesis—the sort used in many central banks—incorporate imperfections in labour markets (“sticky” wages, for instance, which allow unemployment to rise), but make no room for such blemishes in finance. By assuming that capital markets worked perfectly, macroeconomists were largely able to ignore the economy’s financial plumbing. But models that ignored finance had little chance of spotting a calamity that stemmed from it. ­

宏觀經(jīng)濟學家也有一個盲點：他們的標準模式假設資本市場能夠良好運轉,。他們的框架反應了凱恩斯知識繼承人和純粹主義者之間不穩(wěn)定的調和,，凱恩斯承認經(jīng)濟沒能發(fā)揮他的潛力，而純粹主義者認為供求必須一致,。這種合成縮影出的模式——在很多中央銀行使用——合并了勞動力市場里的缺陷（比如導致失業(yè)增加的“黏性”工資）,，卻不能容忍金融上的缺陷。宏觀經(jīng)濟學家假設資本市場良好運轉,，他們就很容易忽視金融系統(tǒng),。但是，忽視金融的模式就不可能發(fā)現(xiàn)一個由金融引起的災難,。­

What about trying to fix it? Here the financial crisis has blown apart the fragile consensus between purists and Keynesians that monetary policy was the best way to smooth the business cycle. In many countries short-term interest rates are near zero and in a banking crisis monetary policy works less well. With their compromise tool useless, both sides have retreated to their roots, ignoring the other camp’s ideas. Keynesians, such as Mr Krugman, have become uncritical supporters of fiscal stimulus. Purists are vocal opponents. To outsiders, the cacophony underlines the profession’s uselessness. ­

該如何補救呢,？金融危機已經(jīng)把純粹主義者和凱恩斯主義者脆弱的共識弄沒了，只有貨幣政策才能讓商業(yè)周期順暢,。很多國家的短期利率接近零,，貨幣政策對銀行業(yè)的危機見效甚微。隨著他們妥協(xié)的手段沒起作用,，雙方都固步自封而無視對方的觀點,。凱恩斯主義者，比如克魯曼就成了政府財政刺激的堅決擁護者,。純粹主義者口頭上反對,。對局外人來說，這種不和諧的聲音凸顯了該行業(yè)的無能,。­

Add these criticisms together and there is a clear case for reinvention, especially in macroeconomics. Just as the Depression spawned Keynesianism, and the 1970s stagflation fuelled a backlash, creative destruction is already under way. Central banks are busy bolting crude analyses of financial markets onto their workhorse models. Financial economists are studying the way that incentives can skew market efficiency. And today’s dilemmas are prompting new research: which form of fiscal stimulus is most effective? How do you best loosen monetary policy when interest rates are at zero? And so on.  ­

綜合這些指責,，明顯是該進行再發(fā)現(xiàn)了，特別是宏觀經(jīng)濟學,。就像經(jīng)濟大蕭條使凱恩斯主義者的大量涌現(xiàn),，二十世紀七十年代的經(jīng)濟停滯與通貨膨脹激起了對抗性反應，具有創(chuàng)造性的銷毀已經(jīng)到來,。中央銀行忙著停止把金融市場映射在他們工作模式這種粗俗分析,。金融經(jīng)濟學家研究刺激如何曲解市場效率。今天的困境推動了新的研究：哪種形式的財政刺激最有效果,？當利率為零時如何最好的放寬貨幣政策,？等等……­

But a broader change in mindset is still needed. Economists need to reach out from their specialised silos: macroeconomists must understand finance, and finance professors need to think harder about the context within which markets work. And everybody needs to work harder on understanding asset bubbles and what happens when they burst. For in the end economists are social scientists, trying to understand the real world. And the financial crisis has changed that world.  ­

但是心態(tài)上更大的改變還是需要的,。經(jīng)濟學家需要從他們專業(yè)簡倉中走出來：宏觀經(jīng)濟學家必須懂得金融，金融專家需要思考市場運轉的環(huán)境,。每個人都需要努力去理解資產泡沫以及泡沫破滅的后果,。最后，經(jīng)濟學家是社會學家,，他們試著去理解真實的世界,。金融危機已經(jīng)改變了世界。­

滬江博客 - Gracie's wonderland - 4