自然抉擇

From The Economist print edition(Oct 12th 2006)

BORN in the trough of the Great Depression， Edmund Phelps， a professor at Columbia University who this week won the Nobel prize for economics， has spent much of his intellectual life studying slumps of a different kind. The Depression， which cost both of his parents their jobs， was exacerbated by the monetary authorities， who kept too tight a grip on the money supply. Mr Phelps is interested in unemployment that even open-handed central bankers cannot cure.

Most scholars stand on the shoulders of giants. But Mr Phelps won his laurels in part for kicking the feet from under his intellectual forerunners. In 1958 William Phillips， of the London School of Economics， showed that for much of the previous hundred years， unemployment was low in Britain when wage inflation was high， and high when inflation was low. Economists were quick—too quick—to conclude that policymakers therefore faced a grand， macroeconomic trade-off， embodied in the so-called “Phillips curve”. They could settle for unemployment of， say， 6% and an inflation rate of 1%—as prevailed in America at the start of the 1960s—or they could quicken the economy， cutting unemployment by a couple of percentage points at the expense of inflation of 3% or so—which is roughly how things stood in America when Mr Phelps published his first paper on the subject in 1967.

In such a tight labour market， companies appease workers by offering higher wages. They then pass on the cost in the form of dearer prices， cheating workers of a higher real wage. Thus policymakers can engineer lower unemployment only through deception. But “man is a thinking， expectant being，” as Mr Phelps has put it. Eventually workers will cotton on， demanding still higher wages to offset the rising cost of living. They can be duped for as long as inflation stays one step ahead of their rising expectations of what it will be.

The stable trade-off depicted by the Phillips curve is thus a dangerous mirage. The economy will recover its equilibrium only when workers' expectations are fulfilled， prices turn out as anticipated， and they no longer sell their labour under 1 pretences. But equilibrium does not， sadly， imply full employment. Mr Phelps argued that inflation will not settle until unemployment rises to its “natural rate”， leaving some workers mouldering on the shelf. Given economists' almost theological commitment to the notion that markets clear， the presence of unemployment in the world requires a theodicy to explain it. Mr Phelps is willing to entertain several. But in much of his work he contends that unemployment is necessary to cow workers， ensuring their loyalty to the company and their diligence on the job， at a wage the company can afford to pay.

“Natural” does not mean optimal. Nor， Mr Phelps has written， does it mean “a pristine element of nature not susceptible to intervention by man.” Natural simply means impervious to central bankers' efforts to change it， however much money they print.

Economists， including some of his own students， commonly take this natural rate to be slow-moving， if not constant， and devote a great deal of effort to estimating it. Mr Phelps， by contrast， has been more anxious to explain its fluctuations， and to recommend measures to lower it. His book “Structural Slumps”， published in 1994， is an ambitious attempt to provide a general theory of how the natural rate of unemployment evolves. Some of the factors that he considered important—unemployment benefits or payroll taxes， for example—are widely accepted parts of the story. Others are more idiosyncratic. He and his French collaborator， Jean-Paul Fitoussi， have， for example， blamed Europe's mounting unemployment in the 1980s in part on Ronald Reagan's budget deficits， which were expansionary at home， but squeezed employment in the rest of the world.

A few years ago David Warsh， an economic journalist， lamented that the glare of the Nobel prize left other equally deserving economists， such as Mr Phelps， languishing “in the half-lit penumbra of the shortlist”. This week， after an unaccountably long lag， professional acclaim for this bold， purposeful theorist finally converged on its natural rate.

譯文:

哥倫比亞大學教授埃德蒙#8226;菲爾普斯，出生于經濟大蕭條谷底時期，本周獲得了諾貝爾經濟學獎。他畢生的學術生涯都在研究另一類型的經濟蕭條。當年，財政當局對貨幣供應控制過嚴，加劇了經濟的衰落，這導致了他父母雙雙失業。而菲爾普斯卻對就連手頭闊綽的央行都無法解決的失業問題感興趣。

大多數學者都是站在巨人的肩上。然而，菲爾普斯獲得此榮譽 ，一部分在于他敢于掙脫前輩的學術桎梏。1958年，倫敦經濟學院的埃德蒙#8226;菲爾普斯指出，前一百多年以來，英國的失業問題與工資引起的通貨膨脹總是此起彼伏，此消彼長。因此，經濟學家們匆忙地決定，指出決策者將面臨一個重要的宏觀經濟平衡，這就是所謂的“菲爾普斯曲線”的一種表現形式。比如說，決策者可以接受6%的失業率和1%的通貨膨脹率，這在美國二十世紀六十年代初是很普遍的。決策者或者以通貨膨脹上升到3%左右為代價，可使就業率降低一兩個百分點，從而加快經濟發展，美國當時的情況大致是這樣。1967年菲爾普斯發表了第一篇關于這一話題的論文。

在如此緊縮的勞動力市場，公司通過提供略高的工資安撫工人。隨后又哄抬物價轉移資本，欺騙工人原本可以更高的真實工資。因此，決策者只需要采取欺騙手段就可以大大降低失業率。但是正如菲爾普斯所說，“人是一個有思想有欲望的生物。”最終，工人們會醒悟，索取更高的工資以彌補與日俱增的生活開支。只要通貨膨脹高于他們對其不斷上升的期望值，他們就可能上當受騙。

于是，菲爾普斯曲線描繪的穩定平衡就成了一種危險的幻想。只有當工人們的期望得到滿足，物價達到期望值，工人們不再在蒙蔽之下出賣自己的勞動力，經濟才有可能恢復平衡。然而，悲嘆的是平衡并非意味著充分就業。菲爾普斯認為，直到失業達到“自然率”，出現了一些閑置人員，通貨膨脹才能得到解決。經濟學家幾乎神學論斷般地信奉這一觀點，即市場要出清，世界失業問題的出現需要一個神學理論去解釋它。菲爾普斯先生樂意醞釀出幾個這樣的理論。不過在他的許多著作中，他爭辯道，失業必然會引起工人的恐慌，這就使得他們對公司忠心不二，對工作兢兢業業，薪水也是在公司所能承受的范圍之內。

“自然”并不意味著最理想。菲爾普斯先生寫道，難道它就意味著“原始的自然元素不易受到人的干擾”。“自然”只不過意味著中央銀行家的努力改變都是徒勞，不論他們印刷了多少鈔票。

經濟學家，其中包括菲爾普斯的一些學生普遍認為自然率要么保持不變要么移動緩慢，花費了大量的精力對其估測。相反，菲爾普斯先生更渴望分析它的波動情況，并且提出降低它的措施。他在他1994年出版的書《結構性蕭條》中，雄心勃勃地嘗試著提出失業自然率演變的一般理論。書中有幾點因素他認為非常重要，譬如說失業津貼或工資所得稅，這些觀點現在都得到了廣泛的認可。其它因素就要特殊些。比如，他和他的法國合作伙伴讓-保羅#8226;菲圖西，責怪二十世紀八十年代歐洲居高不下的失業率一部分責任在于羅納德#8226;里根的預算赤字，不僅導致國內赤字不斷擴大，也降低了世界其它地區的就業率。

幾年前，經濟新聞記者大衛#8226;沃什，悲嘆諾貝爾獎的光輝讓同樣應該獲獎的其它經濟學家如菲爾普斯消逝“在若明若暗的候選人名單的光影中”。本周，不知所以地一拖再拖之后，專家們對這位勇敢堅定的理論家的言辭終于匯集到了他的自然率上。

注:原文出處:雜志《經濟學人》印刷版 2006，10，12

(邱瑩瑩:出生年月1986-9。性別:女，專業:翻譯碩士，方向:英漢筆譯)