隱藏的圖表--為什麼低失業率不再能抬高通膨？

 Hidden figures 隱藏的圖表

Why does low unemployment no longer lift inflation? 為什麼低失業率不再能抬高通膨？

The Phillips curve, the logic of which guides central banks today, has become oddly flat 菲利普曲線，現今央行依循的邏輯指南，變得出奇平坦

Aug 22nd 2020

Every night at about 10pm the lights of the prisoner-of-war camp in Indonesia would mysteriously dim, to the puzzlement of the Japanese guards. They failed to spot the makeshift immersion heaters, used to brew cups of tea for the inmates, that had been cobbled together by a prisoner from New Zealand, William Phillips. These secret contraptions were just one example of his resourcefulness.

每晚10時左右，印尼戰俘營的燈光會神祕地變暗，令日本守衛困惑。他們未發現那些權充浸沒式加熱器的玩意。那是紐西蘭囚犯菲利普（William Phillips）巧手拼湊而成，用來泡茶給獄友喝。這些祕密的發明只是他足智多謀的一例。

After the second world war he built a “hydraulic” model of the circular flow of income in an economy—a labyrinth of water tanks, valves and pipes that helped earn him an appointment at the London School of Economics. But neither of these exploits is the reason why Phillips is known to every economist today. His fame rests instead on his “quick and dirty” study, published in 1958, documenting a striking, decades-long relationship between British wage inflation and unemployment: the one tended to be high when the other was low. A downward-sloping curve, which he drew largely freehand, illustrated the point. The Phillips curve, as it became known, has been described as “probably the single most important macroeconomic relationship”. It has also been called the “least solid piece of work” he ever did.

第二次世界大戰後，他建立了一個經濟所得迴圈流動的「液壓」模型--由水箱、閥門和管子組成的迷宮，這使他贏得倫敦經濟學院的聘任。但是，這兩項功績都不是當今經濟學家無人不知菲利普大名的原因。他的名氣立足於1958年發表的「快速而骯髒的」研究，記錄英國工資通膨與失業之間長達數十年的驚人關係：當一方偏低，另一方就走高。他大致用手繪出一條向下傾斜的曲線，闡述這一點。這就是後來聞名於世的菲利普斯曲線，被描述成「可能是最重要的一種總體經濟關係」，也被稱為他所做過的「最不紮實的研究」。

The Phillips curve’s solidity and shape has been called into question more than once in the past 60 years, including in the period since the global financial crisis of 2007-09. But the logic of the curve still guides central banks today.

菲利普斯曲線的可靠性和形狀，過去60年來不只一次受質疑，包括2007-09年的全球金融危機期間。但是曲線的邏輯仍然指導著今天的央行。

When business is brisk and unemployment low, central bankers worry that workers will demand pay raises over and above inflation and any improvement in their productivity. If firms pass these higher wages on to customers by increasing prices, inflation will rise. If central bankers wish to prevent this, they will raise the interest rate they charge for the money they lend, slowing the economy and curbing the wage pressure.

當商業興隆且失業率低下時，央行官員擔心，勞工要求的加薪幅度將高於通膨率，以及他們生產力的增幅。如果企業藉提高價格將調高的工資轉嫁客戶，通膨率將上升。如果央行希望避免這種情況，他們將提高貸款利率，減緩經濟擴張，並抑制工資壓力。

The opposite happens at the other end of the curve. High unemployment flattens wages and spending, putting downward pressure on inflation. To counteract this, policymakers typically cut interest rates.

相反的情況發生在曲線的另一端。失業率高使工資和支出趨於扁平，造成通膨下降壓力。為抵銷此現象，決策者通常會調降利率。

Central bankers hope to find themselves somewhere in the middle: with inflation where they want it to be and unemployment neither high nor low enough to dislodge it. In these happy circumstances, they aim to set a “neutral” interest rate that will leave inflation where it is.

央行官員希望在兩者之間找到立足點：通膨率位於他們想要的水平，而失業率不至於高到、或低到使通膨率偏離那個水平。在樂觀情況下，他們的目標是設定一個「中性」利率，使通膨率保持不變。

Most central banks in the rich world target an inflation rate of about 2%. At such modest levels, inflation does not greatly complicate financial planning or erode confidence in the currency. But it allows wages to fall modestly, relative to prices, without anyone suffering a thinner pay packet. That cheapening of labour may, in turn, help preserve jobs in a downturn.

大多數富國央行把目標通膨率訂在2％上下。在這種溫和的水平，通膨不會使財務計劃大幅地複雜化，或削弱對貨幣的信心。但這允許工資相對於物價適度下降，卻沒有人會為荷包消瘦所苦，勞動力變便宜，到頭來可能有助於在景氣低迷時保住工作。

In recent years, however, inflation has fallen persistently short of the central bank’s target in many countries. In the immediate aftermath of the global financial crisis, such low inflation was no puzzle. Unemployment rose sharply, reaching 10% in America in October 2009. In those circumstances, the only surprise was that inflation did not fall further. But after the recovery inflation continued to remain muted even as unemployment in America, the euro area and Japan fell unusually far. That has forced economists to rethink the relationship.

但是近年來，許多國家的通膨率一直低於央行目標。全球金融危機爆發後，如此低的通膨不足為奇。失業率急劇上升，美國在2009年10月達到10％。在這種情況下，唯一令人訝異的是通膨率沒有降得更低。然而，經濟復甦之後，通膨率持續文風不動，即使美國、歐元區和日本的失業率降幅大得異常。這迫使經濟學家重新思考兩者關係。

In the 1960s some sceptics, perhaps most notably Milton Friedman, pointed out that the relationship between unemployment and inflation is only as solid as the expectations that underlie it. If inflation is expected to be 2%, then workers emboldened by low unemployment might demand a wage increase of 3 or 4%. But if inflation is expected to be 10%, then similarly emboldened workers might demand a wage increase of 11% or more. In the 1970s, high inflation persisted despite high unemployment precisely because workers’ expectations of inflation had risen so much. Economists decided to “augment” the Phillips curve by adding expectations alongside unemployment as a separate determinant of inflation.

1960年代一些懷疑論者（其中最受關注的或許是傅利曼）指出，失業率與通膨率之間的關係，就像背後的預期一樣牢靠。如果通膨率預計為2％，勞工可能因失業率低而放膽要求加薪3%或4％。但若預計通膨率為10％，勞工同樣可能有恃無恐地要求加薪11％或更多。在1970年代，儘管失業率很高，通膨率持續居高不下，正是因為勞工對通膨的預期大幅提高。經濟學家決定「擴充」菲利普曲線，加入通膨預期，與失業率並列為決定通膨的獨立因素。

Another complication comes from imports. Unemployment at home has little bearing on wages abroad. The price of anything consumers buy from the rest of the world will be determined by other forces. For this reason, some economists add a measure of import prices to the curve.

另一個複雜因素來自進口。國內的失業對海外的工資影響微乎其微。消費者從世界各地買來的任何產品的價格，取決於其他力量。因此，一些經濟學家把進口物價指標也加入曲線。

Neither of these additions, however, can explain the missing inflation of recent years. Imports from countries like China may have depressed the price of some products, such as electrical appliances. But that is no reason why prices in general should be subdued. If China is holding down the price of one corner of the shopping basket, the central bank should be able to encourage other prices to rise to offset it. Inflation of 2% is perfectly compatible with some prices dropping steeply, as long as enough others rise sufficiently fast.

然而，添加了這些，還是不能解釋為何近年來通膨消失無蹤。從中國大陸等國進口產品，可能壓低了某些產品的價格，例如家用電器。但這絕不是整體物價遭壓抑的原因。如果中國大陸壓低購物籃一角的物價，央行應有能力鼓勵其他價格上漲，予以抵消。2％的通膨率絕對可以包容某些物價陡降，只要夠多的其他產品漲幅夠大即可。

Inflation expectations can also explain only part of the puzzle. They have been low for decades: in America, they have not exceeded 3% for 20 years, according to the Federal Reserve Bank of Cleveland. These subdued expectations have shifted the Phillips curve downwards, so that a given rate of unemployment is associated with a lower rate of inflation.

通膨預期也只能解釋一部分謎團。它們已經低迷幾十年：美國已經20年沒有超過3％，根據克利夫蘭聯邦準備銀行數據。這些低迷的預期使菲利普曲線向下移動，因此特定的失業率與較低的通貨膨脹率產生關聯。

Middle of the riddle 謎霧之中

But what has happened to the curve in recent years is different: more akin to a rotation, rather than a shift up or down. Inflation has become seemingly insensitive to joblessness, yielding a curve that has become strangely flat. This may be because the unemployment rate misstates the amount of spare capacity or “slack” in the economy. By 2019 unemployment in America, Europe and Japan had fallen to surprisingly low levels, which tempted some people on the periphery of the labour force back into work. Japan’s firms found room to grow by hiring many women and old folk who had not been counted as unemployed.

但是，近年來曲線發生不同的變化：比起向上或向下移動，更像是旋轉。通膨似乎對失業不敏感，產生的曲線變得異常平坦。這可能是因為失業率錯誤陳述閒置產能的量，或經濟「疲軟」的程度。到2019年，美國、歐洲和日本的失業率已降到令人驚訝的低水平，這吸引部分處於勞動力邊緣的人重返就業市場。日本公司找到了成長空間，僱用許多未被算成失業者的婦女和老人。

Inflation may also be slow to rise in a jobs boom for the same reason it is slow to fall in a bust. In downturns, firms are reluctant to lower wages, because of the harm to staff morale. But because they refrain from cutting wages in bad times, they may delay raising them in good. According to this view, wages will eventually pick up. It just takes time. And many other things, like a pandemic, can intervene before they do.

通膨在就業市場繁榮時也可能緩慢上升，跟不景氣時緩慢下降的原因相同。在低迷時期，公司不願降低工資，因為這有損員工士氣。但是，正因他們避免在艱困時期削減工資，繁榮時期可能延遲提高工資。根據這種觀點，工資終將回升，只是需要時間。還有許多其他因素，例如大流行病，也可能是工資上揚前的干預因素。

The impact of low unemployment would be easier to spot in the data if it were not so rare, according to Peter Hooper of Deutsche Bank, Frederic Mishkin of Columbia University and Amir Sufi of the University of Chicago in a paper published in 2019. To increase the number of observations, they unparcelled America into its separate states and cities. At this subnational level, they found numerous examples of red-hot jobs markets over the past few decades, and a clearer link to wage and price inflation. The local Phillips curve is “alive and well”, they note, and perhaps the national version is just “hibernating”.

低失業率的影響若不是那麼罕見，否則本應更容易在數據中發現，德意志銀行的霍珀（Peter Hooper）、哥倫比亞大學的米什金（Frederic Mishkin）和芝加哥大學的蘇菲（Amir Sufi）在2019年發表的論文中這麼說。為提高觀察點，他們將美國分拆成個別的州和城市。在國家以下的層級，他們發現過去幾十年眾多就業市場火熱的例證，工資和物價上漲的關聯也更清晰了。他們指出，各地的菲利普曲線仍然「生氣蓬勃」，也許全國版曲線只是在「冬眠」。

It may also take time for higher wages to translate into dearer prices. In bustling fruit-and-vegetable markets stalls display their prices in chalk, making them easy to scrub out and revise. But for many other firms, changing prices is costly. When inflation is low, they may change prices only infrequently: it does not seem worth printing a new menu just to change prices by 2%. This inertia, however, also means firms rarely have the opportunity to reprice their goods to reflect swings in their business. The economy has to move a lot before prices will move at all.

工資上漲也可能需要一些時間，才能轉化為物價上漲。在交易繁忙的果菜市場，攤販用粉筆標示價格，很容易擦掉修改。但是對其他許多公司來說，調整價格要付出昂貴代價。通膨低迷時，可能偶爾才調整售價：只為漲價2％而重印菜單，似乎不值得。不過，這種惰性也意味公司很少有機會對產品重新定價，以反映市況起伏。經濟必須歷經重大變化，價格才會有所變動。

Although the flat Phillips curve puzzles central banks as much as anyone, they may be partly responsible for it. The curve is supposed to slope downwards (when inflation or unemployment is high, the other is low). But central banks’ policies tilt the other way. When inflation looks set to rise, they typically tighten their stance, generating a little more unemployment. When inflation is poised to fall, they do the opposite. The result is that unemployment edges up before inflation can, and goes down before inflation falls. Unemployment moves so that inflation will not.

儘管平坦的菲利普曲線，使央行和其他人一樣困惑，但他們可能得負部分責任。該曲線照理說應該向下傾斜（當通膨率或失業率在高點時，另一個則在低點）。但是央行政策總向另一邊傾斜。當通膨看起來會上升時，他們通常會緊縮立場，引發更多的失業。當通膨率準備下降時，他們就反其道而行。結果造成失業率在通膨上升之前先上升，在通膨下降之前下降。結果失業率變動，但通膨率不動。

The relationship between labour-market buoyancy and inflation still exists, according to this view. And central banks can still make some use of it. But precisely because they do, it does not appear in the data. “Who killed the Phillips curve?” asked Jim Bullard, an American central banker, at a conference of his peers in 2018. “The suspects are in this room.”

根據這種觀點，勞動市場起伏與通膨之間的關係仍然存在，央行仍然可以稍加運用。但正因他們這麼做，數據才反映不出來。 「誰殺了菲利普曲線？」美國央行官員布拉德（Jim Bullard）在2018年與同事開會時問道。「嫌疑犯就在這個房間裡。」

But what happens when the killers run out of ammunition? To keep the Phillips curve flat, central banks have to be able to cut interest rates whenever inflation threatens to fall. Yet they can run out of room to do so. They cannot lower interest rates much below zero, because people will take their money out of banks and hold onto cash instead.

但是，一旦殺手的彈藥耗盡，會發生何事？為了使菲利普曲線保持平坦，央行一察覺通膨有下降之虞，就必須降低利率。但他們可能沒有餘裕這麼做了：不能把利率降到遠低於零，因為這會促使人們從銀行提款，寧可抱持現金。

When Mr Bullard spoke, the Federal Reserve expected the economy to continue strengthening, allowing it to keep raising interest rates. But that proved impossible. The Fed was able to raise interest rates no higher than 2.5% before it had to pause (in January 2019) then reverse course. The neutral interest rate proved to be lower than it thought. That left it little room to cut interest rates further when covid-19 struck.

布拉德發言當時，聯準會（Fed）還預期經濟仍將走強，可持續提高利率。但事後證明這是不可能的。Fed只把利率升到2.5%，就必須暫停升息（在2019年1月），然後更改弦易轍。中性利率證明比Fed預期來得低。新冠病毒來襲時，Fed進一步降息的空間寥寥無幾。

The neutral interest rate has fallen, according to some observers, because of global capital flows. Heavy saving by the world’s ageing populations has resulted in too much money chasing too few investments. By lowering the neutral rate, this “global savings glut” has left central banks closer to the floor on interest rates than they would like. That has made it harder for them to offset any additional downward pressures on prices.

一些觀察家認為，由於全球資本流動，中性利率已經下降。全球高齡化人口大量儲蓄，導致太多的資金追逐太少的投資標的。這種「全球儲蓄過剩」使中性利率下降，造成各國央行比預期更接近利率下限。這使他們更難抵消物價進一步走低壓力。

Friedman thought central banks could prevent inflation if sufficiently determined to do so. “There is no technical problem about how to end inflation,” he wrote in 1974. “The real obstacles are political.” Is reviving inflation any different? Central banks face two technical limits. First, they cannot lower interest rates much below zero. And they can only purchase financial assets, not consumer goods. Central banks can create unlimited amounts of money. But they cannot force anyone to spend it.

傅利曼認為，央行如果下足決心，可以防止通膨。他在1974年寫道：「終結通貨膨脹沒有技術上的問題。真正的障礙是政治上的。」通膨復熾有什麼不同？央行面臨兩個技術限制。首先，他們不能將利率降到遠低於零。其次，他們只能買金融資產，不能買消費品。央行可以印製無限量的錢幣，卻不能強迫任何人花錢。

One solution is to work in tandem with the government, which can spend any money the central bank creates. Before covid-19, such dalliances were rare. But an increasing number of central banks, in both the rich and emerging world, are changing course. These partnerships will try to stop pandemic-related unemployment turning low inflation into outright deflation. If they fail it will be an economic disaster: mass joblessness coupled with negative inflation. And it will be no consolation to students of economics that this combination will remove the flatness from one of their discipline’s most famous curves. ■

一種解決方法是與政府協力合作，央行印多少鈔票，政府就可花掉多少。在新冠肺炎疫情前，這種眉來眼去很少見。但是，愈來愈多的央行都在改變路線，富國和新興國家皆然。有了這些夥伴關係，可試著阻止疫情相關失業把低通膨變成徹底的通縮。如果失敗，那將是場經濟災難：大規模失業和通縮。這種結合將移除經濟學著名曲線的平坦性，但對研究經濟學的人毫無慰藉可言。 ■

努力工作和黑天鵝--經濟學家轉用文化解釋貧富

 Hard work and black swans 

努力工作和黑天鵝

Economists are turning to culture to explain wealth and poverty 

經濟學家轉用文化解釋貧富

As a result, the ideas of the earliest economists are being revised and improved

因此修正、改善早期經濟學家的觀念

Schools brief

Sep 3rd 2020 edition

Sep 3rd 2020

The emergence of the discipline of economics in the 18th century was the result of people trying to explain something that had never happened before. At the time a handful of countries were becoming fabulously rich, while others remained dirt-poor. In 1500 the world’s richest country was twice as well-off as the poorest one; by 1750 the ratio was five to one. It is no coincidence that the most famous book in economics, published in 1776, inquired into “the Nature and Causes of the Wealth of Nations”.

人們試圖解釋前所未見的事，於是經濟學科在18世紀應運而生。當時，一小撮國家變得異常富裕，其他國家仍一貧如洗。1500年，世上最富國的財力是最窮國的兩倍。到1750年，這比例達到五比一。1776年，經濟學領域最出名的著作出版，探討「國家財富的性質和成因」，這並非巧合。

In order to explain such a divergence between rich and poor countries, the early economists were obsessed with culture, a catch-all term encompassing a society’s beliefs, preferences and values. Adam Smith, the author of “The Wealth of Nations”, explored the ways in which culture helped or hindered capitalism. He argued that certain norms were required in order for market economies to thrive—most importantly, that people would be self-interested, but that they would satisfy their self-interest by adapting to the needs of others. Karl Marx, a few decades later, worried that a culture of “oriental despotism” prevented the emergence of capitalism in Asia.

為解釋富國和窮國為何差異這麼大，早期的經濟學家迷上了「文化」，一個包羅萬象的用語，涵蓋社會信仰、偏好和價值觀。 《國富論》的作者亞當·史密斯（Adam Smith）探索文化如何助長或阻礙資本主義。他主張某些規範是促進市場經濟繁榮所必需的--最重要的是，人們是自私自利的，但他們會藉順應他人的需求來滿足私利。幾十年後，馬克思（Karl Marx）擔心，「東方專制」文化阻礙了資本主義在亞洲崛起。

The speculations of Smith, Marx and others were often vague. Max Weber’s “The Protestant Ethic and the Spirit of Capitalism”, published in 1905, made them concrete. Weber argued that Protestants, in particular Calvinists, drove the emergence of capitalism due to a strong work ethic.

史密斯、馬克思和其他人的推測常含糊不清。韋伯（Max Weber）於1905年出版的「新教徒的資本主義倫理與精神」使之具體化。韋伯主張，新教徒（尤其是喀爾文主義派），基於強烈的職業道德，推動了資本主義的出現。

In the middle of the 20th century such cultural explanations began to fall out of favour. The rapid rise of Japan’s economy in the 1950s, and later of the Asian “tigers”, quashed the Marxist-Weberian notion that Western culture alone was conducive to industrialisation. At the same time the increasing availability of data with which to do statistical analysis meant that economists’ attention went elsewhere. Why bother with hard-to-measure matters such as morals, when it is possible to plug hard data such as capital accumulation, wages or employment into a regression model? In 1970 Robert Solow, a Nobel prizewinner, quipped that attempts to explain economic growth with reference to culture ended up “in a blaze of amateur sociology”.

在20世紀中葉，這種文化解釋開始失寵。 1950年代日本經濟以及後來亞洲「四小龍」快速崛起，推翻馬克思與韋伯所謂只有西方文化才能促成工業化的觀念。同時，可用來做統計分析的數據愈來愈俯拾即得，經濟學家的注意力轉移他處。既然可能將資本累積、工資、就業等硬數據導入迴歸模型，又何必煩惱像道德這種難以測量的問題？ 1970年，諾貝爾獎得主梭羅（Robert Solow）打趣說，企圖參照文化來解釋經濟成長，最後落得以「一股業餘社會學狂熱」收場。

But an interest in culture remained—and indeed is now making a comeback. Since the 1980s datasets such as the World Values Survey and the General Social Survey have made it easier to quantitatively measure cultural preferences and relate them to economic outcomes. Top economic journals now regularly include papers on the importance of culture. Even many hardline wonks have come to realise the limits to pure economic reasoning.

但是對文化的興趣仍在，事實上，現在正捲土重來。自1980年代以來，有了「世界價值觀調查」和「一般社會調查」這類資料庫，更容易量化文化偏好，並與經濟結果聯繫起來。頂尖經濟期刊現在定期收錄探究文化重要性的論文。就連許多強硬派的權威，也開始體認到純經濟推理的局限。

Perhaps the most influential text in the revival of cultural economics was “Making Democracy Work”, a book from 1993 by Robert Putnam. Mr Putnam tried to understand why for many decades northern Italy had been richer than the south, folding the explanation under the catch-all term “social capital”. 

對文化經濟學的復興最具影響力的著作，也許是1993年普特南（Robert Putnam）所著的《使民主運轉起來》。普特南試圖理解，為什麼數十年來義大利北部一直比南部富庶，並把他的解釋概括於「社會資本」一詞底下。

People in the south were fiercely loyal to their family, but more distrustful of outsiders—whereas in the north people were happier to form connections with strangers, Mr Putnam argued. In the north people read more newspapers, were more likely to participate in sports and cultural associations, and voted more frequently in referendums. This, the theory went, contributed to better local government and more efficient economic transactions, which in turn produced greater wealth—though Mr Putnam was not clear about the precise mechanism by which one thing led to the other.

普特南指稱，南方人極忠於家人，但對外人較不信任；北方人則更樂於與陌生人建立聯繫。北方人閱讀更多報紙，更可能參加體育和文化協會，也更常參與公民投票。照理說，這會促成更好的地方政府、提高經濟交易效率，進而產生更多的財富--儘管普特南未說明究竟是什麼機制導致這些因果關係。

A group of researchers, largely dominated by Italians who were inspired by Mr Putnam’s work, has since extended his ideas, seeking cultural explanations of why some areas are rich and others poor. A paper from 2004 by Luigi Guiso, Paola Sapienza and Luigi Zingales, also looking at Italy, finds that in high-social-capital areas, households invest less in cash and more in stocks, and make less use of informal credit. In areas where people do not really “trust those outside their family, it may be hard to form large business organisations which can benefit from economies of scale and which can drive the adoption of new technologies. This suggests that it is no coincidence that the average business in Lombardy, a rich northern region in Italy, has 13 employees, compared with five in Calabria, a poor southern one.

受到普特南的研究啟發，一群由義大利人主導的研究人員擴展了他的想法，從文化解釋為什麼某些地區富裕而另一些地區貧困。 圭索（Luigi Guiso）、薩皮恩扎（Paola Sapienza）和津加莱斯（Luigi Zingales）於2004年發表的一篇論文，同樣觀察義大利，發現在社會資本高的地區，家庭對現金的投資較少，股票的投資較多，並較少使用非正式信貸。在人們不太「信任家人外的人」的地區，可能難以形成大型商業組織，這類組織不但受益於規模經濟，也推動採用新技術。這顯示，義大利富裕的北部地區倫巴底，企業平均有13名員工，南部貧困的卡拉布里亞平均只有五名員工，絕不是巧合。

Others look beyond Italy. In “A Culture of Growth”, published in 2016, Joel Mokyr of Northwestern University puts the “principle of contestability” as the reason why some countries industrialised but others did not. Organisations such as the Royal Society, founded in London in 1660, were forums for the exchange of ideas, where people put forward their discoveries and fiercely interrogated the theories of others. Crucially, too, over time the goal of western European science shifted from one concerned with the “mindless piling up of empirical facts”, as Mr Mokyr puts it, towards discoveries which could be put to use in the real world. Scientific inquiry laid the groundwork for European economic exceptionalism. Nothing quite comparable happened in other parts of the world.

其他人放眼義大利以外地區。西北大學的莫基爾（Joel Mokyr）在2016年出版的《成長的文化》中將「可競爭性原則」做為國家實現工業化與否的原因。像1660年在倫敦成立的皇家學會這類組織，是交流思想的論壇，人們在那裡提出自己的發現，並嚴厲審問他人的理論。同樣重要的是，久而久之，用莫基爾的話來描述，西歐科學的目標從「漫不經心堆積經驗事實」，轉向可應用在現實世界的發現。科學探究為「歐洲經濟特殊論」奠定基礎，這在全世界無可比擬。

Culture club 文化俱樂部

The revival of cultural explanations for wealth and poverty seems to be a methodological step forward. Yet it raises two big questions. The first concerns the origins of cultural traits: where do they come from? The second is why people from apparently similar cultures sometimes have very different economic outcomes. To answer these questions, economists have come to appreciate the importance of history—and, in particular, historical accident.

從文化角度解釋貧富的做法再度盛行，似乎是方法論的進步。然而這引發兩大問題。第一個涉及文化特質的起源：它們來自何處？第二個問題是，為什麼文化明顯相似的國家，有時會產生截然不同的經濟結果。為回答這些問題，經濟學家開始評估歷史的重要性，特別是歷史的偶發事件。

Take first the question of the origin of cultural traits. Some research suggests that they are the product of changes which took place hundreds of years ago. A 2013 paper by the late Alberto Alesina and two of his colleagues looks at why countries have very different rates of female labour-force participation. Egypt and Namibia are about as rich as each other, but the share of Namibian women in the labour force is more than twice that of Egyptian women. The paper puts such differences largely down to differences in pre-industrial agriculture and environmental conditions. Plough cultivation, common in Egypt, required lots of upper-body strength—so men were at an advantage. Shifting cultivation, more common in Namibia, used hand-held tools like the hoe which suited women better. The effect of these agricultural technologies echoes in statistics today.

先談文化特質起源的問題。一些研究顯示，它們是源自於數百年前發生的變化。已故的阿萊西那（Alberto Alesina）和兩個同事在2013年發表一篇論文，探討各國女性勞動參與率差異懸殊的原因。埃及和納米比亞富裕程度不相上下，但納米比亞婦女在勞動力的占比是埃及婦女的兩倍以上。該論文將這種差異主要歸因於工業化前農業和環境條件的差異。犁耕在埃及很普遍，需要大量的上半身力量，因此男人占優勢。輪耕在納米比亞較常見，使用如鋤頭的手持工具，更適合女性。這些農業技術的影響在當今的統計數據上得到印證。

Other economists look to the distant past to explain contemporary disparities in income and wealth. A paper from last year by Benjamin Enke of Harvard University finds evidence that pre-industrial ethnicities which were exposed to a high local prevalence of pathogens exhibited tighter kinship systems—meaning, in effect, that people were strongly loyal to their extended family but suspicious of outsiders. In a place threatened by disease, tight family ties were beneficial because they reduced the need to travel, and therefore the risk of being exposed. Places which had tighter kinship systems hundreds of years ago tend to be poorer today, a relationship which first emerged during the industrial revolution. Other research has looked even further back, suggesting that contemporary cultural traits are the result of genetic variation. But this remains a niche pursuit, and most economists turn queasy when it comes to talking about genetics.

其他經濟學家則追溯到遙遠的過去，來解釋當代收入和財富不平等。哈佛大學的恩克（Benjamin Enke）去年的一篇論文發現，有證據證明，工業時代前的種族若暴露於當地感染率高的流行病，會展現更緊密的親屬關係----事實上，這意味人們對大家庭極為忠誠，但對外人有戒心。在一個受疾病威脅的地方，緊密的家庭關係是有益的，因為旅行的必要降低，染病風險因而減少。幾百年前血緣關係愈緊密的地方，如今往往更窮，這種關係最早在工業革命時期顯現。其他研究追溯得更久遠，發現當代文化特質是基因變異的結果。但這仍屬小眾型研究，大多數經濟學家談到遺傳學都變得侷促不安。

A separate body of research focuses on cases where culture is not a sufficient explanation for economic outcomes. Take the case of Guatemala and Costa Rica. “The two countries had similar histories, similar geographies and cultural inheritance, and were faced with the same economic opportunities in the 19th century,” write Daron Acemoglu and James Robinson in “The Narrow Corridor”, a book published last year. But today the average Costa Rican is more than twice as rich as the average Guatemalan. The cause of the divergence initially appeared random, according to Mr Acemoglu and Mr Robinson. Eventually it became clear it was down to coffee. In Costa Rica the development of coffee plantations for the European market led to a more balanced relationship between state and society, possibly because the country had more marginal land and more smallholders. In Guatemala, by contrast, it led to the emergence of a rapacious government.

另一派研究聚焦的個案，是文化不足以解釋經濟結果的情況 [叮嚀一句：outcome是結果，可能有好有壞；「成果」則多半指好的結果]。以瓜地馬拉和哥斯大黎加為例，「兩國擁有相似的歷史、相似的地理和文化傳統，在19世紀也面臨相同的經濟機會」，阿齊默魯和羅賓遜在去年出版的《狹窄的走廊》書中寫道。如今，哥斯大黎加人的平均收入是瓜地馬拉人的兩倍多。 阿齊默魯和羅賓遜說，起初造成這種分歧的原因似乎是隨機的，後來則明顯歸因於咖啡。哥斯大黎加為歐洲市場開發的咖啡種植園，導致國家與社會之間的關係更加平衡，這可能是因為有更多的邊際土地和更多的小農。相形之下，在瓜地馬拉，則導致強取豪奪的政府出現。

In addition to culture, therefore, a growing band of economists is looking at “institutions”, often taken to mean the legal system and regulations. Some cultural economists argue that the focus on institutions proves their point: what are institutions if not the product of norms, values and preferences? Americans’ and Europeans’ differing beliefs about the causes of inequality, for instance, go a long way towards explaining why European welfare states are more generous than America’s.

因此，除文化外，愈來愈多的經濟學家開始關注「制度」，通常指法規制度。一些文化經濟學家主張，聚焦於制度證明他們的觀點：制度若不是規範、價值觀和偏好的產物，那會是什麼？美國人和歐洲人對--比方說--不平等成因的看法不同，對解釋為何歐洲福利國家比美國更慷慨大有幫助。

But in many cases the emergence of different institutions may have nothing to do with a country’s culture. Sometimes it is just luck. Mr Mokyr shows that Europe, which was fragmented into lots of states, was the perfect setting for innovation: intellectuals who challenged received wisdom and incurred the wrath of the authorities could move elsewhere (Thomas Hobbes wrote “Leviathan” in Paris). By contrast in China, Mr Mokyr argues, free thinkers had few escape routes. Europeans did not plan such a system. It just happened.

但在許多情況下，不同制度的出現可能與一國的文化無關。有時只是運氣。據莫基爾闡述，歐洲四分五裂成眾多國家，是創新的完美環境：知識分子若挑戰既有觀念並觸怒當局，可以遷往別處（托馬斯‧霍布斯在巴黎寫下《利維坦》）。對照下，莫基爾指出，中國的自由思想家的逃生路線很少。歐洲人並未規劃這樣的體系，但就這麼形成了。

Other work by Mr Acemoglu and Mr Robinson, along with Simon Johnson of MIT, has found a further element of randomness which may explain contemporary patterns of wealth and poverty—namely, which countries are more prone to certain diseases. The mortality rate of settlers was low in some colonised countries, such as New Zealand and Australia, in part because the kinds of diseases that were there were less virulent.

阿齊默魯和羅賓遜及麻省理工學院的詹森（Simon Johnson）的其他研究，發現了隨機性的另一個要素，可以解釋當代的貧富模式----即哪些國家更容易遭某些疾病打擊。在一些殖民地國家，例如紐西蘭和澳大利亞，移民的死亡率很低，部分原因是當地疾病的毒性較低。

In others, such as Mali and Nigeria, mortality rates were far higher. Colonisers did not want to settle in countries with a high risk of disease, even as they wanted to take those countries’ raw materials. So in countries such as Mali and Nigeria, rather than permanently settling, they set up systems which enabled the maximum of resource extraction with the fewest boots on the ground. That, say Messrs Acemoglu, Johnson and Robinson, produced rapacious political systems which have endured to this day.

在其他國家，例如馬利和奈及利亞，死亡率要高得多。殖民者不願在疾病風險高的國家定居，即使他們想奪取這些國家的原物料。因此，在馬利和奈及利亞等國家，他們不是想要永久定居，建立制度只為能夠以最少的地面兵力開採最大限度的資源。阿齊默魯、羅賓遜和詹森說，這種貪婪的政治制度延續至今。

Are economists any closer to answering the foundational question of their science? Far from the simplistic certainty of Weber, it seems likely that some countries are rich and others poor because of a messy combination of economic incentives, culture, institutions and chance—which is most important remains unclear. In 1817 Thomas Malthus, one of the early economists, wrote in a letter to David Ricardo, another, that “the causes of the wealth and poverty of nations [were] the grand object of all enquiries in Political Economy”. The revival of cultural economics two centuries on has helped in that quest, but it is not over yet. ■

經濟學家是否更接近於回答其學科的基本問題？迥異於韋伯單純、肯定的答案，一國是貧是富的成因，似乎可能是包含經濟動機、文化、制度和巧合的大雜燴，何者是最重要因素仍不明。 早期經濟學家馬爾薩斯（Thomas Malthus）1817年在寫給另一位經濟學家里卡多（David Ricardo）的信中寫道：「造成國家貧富的原因，是政治經濟學所有研究中最宏大的目標。」隔兩個世紀後，文化經濟學復興對答案的追尋雖有助益，但那場追尋尚未結束。 ■

美元主場：振作點--全球貿易依賴美元因而減少其益處

Greenback dominance: Buck up.

美元主場：振作點

Global trade’s dependence on dollars lessens its benefits

全球貿易依賴美元因而減少其益處

Policymakers around the world yearn to be free of the greenback’s grip

世界各地政策制定者渴望擺脫美元的束縛

Schools brief

Aug 27th 2020 edition

Aug 27th 2020

Crashing currencies hurt. They make imports more expensive, cutting into household budgets and raising businesses’ costs. But economics has long held that this pain brings with it its own salve. More expensive imports should drive new demand for home-made replacements and thus for the workers who make them, geeing up the economy. What is more, a devalued currency means exports are suddenly cheaper to buyers abroad. That, too, should boost demand. When the value of the Colombian peso collapsed in the summer of 2014, it was on the basis of these assumptions that the country’s finance minister greeted the fall as “a blessing in disguise”.

貨幣崩跌很傷。它使進口更加昂貴、侵蝕家庭預算，並增加企業成本。但是經濟學長期主張，這種痛苦附帶自我緩解。舶來品更昂貴，應能激起對國產替代品及其製造勞工的新需求，進而催動經濟。而且，貨幣貶值意味出口貨物對國外買家突然變便宜，這也應該能助長需求。哥倫比亞貨幣披索2014年夏天暴跌時，哥國財政部長正是基於這些假設，將匯率下跌視為「變相的祝福」。

It wasn’t. There were, the IMF opined in a subsequent report, a number of reasons for this, many specific to Colombia. But one problem was a factor which is embedded in the machinery of today’s international commerce. Colombia does not trade in pesos. It trades almost exclusively in dollars; 98% of its exports are invoiced in them. This is an extreme example of a general point. The amount of trade carried out in American dollars vastly exceeds the amount that America imports and exports. Although that may seem like a detail of book-keeping, it matters a lot. A growing body of evidence suggests that the dollar’s prominence in trade undermines the advantages which flexible exchange rates are meant to offer. And when the dollar strengthens, global trade tends to contract.

但它不是祝福。國際貨幣基金（ IMF）在隨後的報告中指出，這是多種因素造成，其中許多為哥倫比亞所特有。但問題是，有個因素嵌入當今國際商務機制。哥倫比亞對外貿易不用披索，幾乎只用美元，98％的出口都以美元計價。這是共通問題的一個極端例子。以美元進行的貿易額，遠大於美國的進出口額。儘管這似乎只是簿記的一個細節，卻極為重要。愈來愈多證據顯示，美元在貿易的重要地位，破壞彈性匯率理應提供的優勢。一旦美元走強，全球貿易趨於萎縮。

For decades, economists’ thinking about trade and currencies was summarised in a model created in the 1960s by two researchers at the IMF, Robert Mundell and J. Marcus Fleming. They assumed no special role for any dominant currency, but rather that traders would agree on prices in the exporter’s currency. A Colombian devaluation, say, would immediately turn peso-priced batteries into bargains abroad, encouraging foreign buyers to scoop up more of them. Meanwhile shoppers in Bogotá wanting to buy Brazilian T-shirts would resent being made to fork out more pesos to cover the price fixed in real.

兩位IMF研究員孟代爾（Robert Mundell）和佛萊明（J. Marcus Fleming）在1960年代創建的模型，總結了幾十年來經濟學家對貿易和貨幣的思考。他們假設，沒有任何主導貨幣承擔特殊角色，而是貿易商議定以出口方貨幣支付的價格。比方說，哥倫比亞貨幣若是貶值，以披索計價的電池立刻在國外變成便宜貨，鼓勵外國買家擴大收購。同時，波哥大的購物者若想買巴西T恤，可能埋怨被迫掏出更多披索來補足以里爾（巴西幣）訂的售價。

This simplifying assumption was potentially consequential. As early as 1947, Joan Robinson of the University of Cambridge noted that the currency companies used for invoicing could mute the expenditure-switching effect. If the prices of Colombian exports were in dollars, not pesos, a devaluation would leave prices faced by American importers—and their demand—unaffected. But though that might matter in principle, did it matter much in practice?

這種簡化的假設可能產生重要的影響。早在1947年，劍橋大學的羅賓遜（Joan Robinson）指出，簽發匯票的換匯公司可能會削弱支出轉換的效果。如果哥倫比亞出口以美元計價，而不是披索，那麼哥幣貶值對美國進口商與其需求來說，價格不受影響。但是，儘管那在原則上可能很重要，實務上是否也很重要?

In 1973 Sven Grassman of the Institute for International Economic Studies used Swedish data to answer in the negative. He found that in 1968 around two-thirds of Swedish trade had been indeed invoiced in the currency of the exporter. This “fundamental symmetry in international payment patterns” became known as “Grassman’s Law”. Swedish exports to America, which were mostly invoiced in dollars not kronor, were written off as the exception. That suggested that Mundell and Fleming were right.

1973年，國際經濟所的格拉斯曼（Sven Grassman）研究瑞典的數據後，做出否定的回答。他發現在1968年，瑞典約三分之二的貿易確實是以出口商的貨幣計價。這種「國際支付方式的基本對稱性」被稱為「格拉斯曼法則」。瑞典對美國的出口大多以美元計價，而非克朗。這表明孟代爾和佛萊明是正確的。

Over the next decades more data further supported Grassman’s Law—always with the same American exception. But by the 1990s some researchers were beginning to doubt its validity. Their main argument was that the actual prices of goods did not vary as much or as quickly as would be expected if payments were in fact symmetrical. Grassman’s Law said that the price of Brazilian T-shirts in Colombian markets should vary with the peso-real exchange rate, for example. But such prices were in fact much stickier.

往後幾十年，更多的數據進一步支持了格拉斯曼法則—--美國始終是特例。但是到1990年代，一些研究人員開始懷疑其有效性。他們的主要論點是，如果付款實際上是對稱的，商品實際價格的變化不會如預期的那樣大或快。舉例來說，按格拉斯曼法則，以哥倫比亞市場上巴西T恤的價格，應該隨著披索/里爾的匯率而變化。但這些價格實際上更加黏著不動。

In the mid-2000s Linda Goldberg and Cedric Tille of the Federal Reserve Bank of New York compiled data describing 24 countries in the late 1990s and early 2000s. This confirmed that Grassman’s Law was wrong: exports were not generally priced in the currency of the country they came from. In 2001, for example, they found that South Korea invoiced 82% of its imports in dollars, despite only 16% of its imports coming from America.

在2000年代中期，紐約聯邦準備銀行的戈柏（Linda Goldberg）和蒂爾（Cedric Tille）匯編1990年代末和2000年代初描述24國的數據，這證實格拉斯曼法則是錯的：出口產品通常不以出口國的貨幣計價。例如在2001年，他們發現，韓國82％的進口以美元計價，儘管只有16％的進口貨物來自美國。

Other work confirmed and updated their findings: the dollar has a huge role as a “vehicle currency” in which to invoice transactions to which no Americans are party, particularly in developing countries. Gita Gopinath of the IMF has compiled data covering just over half of world trade to show that the dollar’s share of invoicing was 4.7 times larger than America’s share of the value of imports, and triple its share of world exports. Another IMF study showed that the dollar’s share has not decreased in step with America’s declining share of overall trade.

其他研究也證實並更新他們的發現：即使沒有美國人參與匯票貿易，美元仍扮演著重大的「媒介貨幣」角色，特別是在發展中國家。IMF的戈皮納特（Gita Gopinath）匯整涵蓋全球逾半數貿易的數據，顯示美元的匯票額占比，較美國的進口額占比高4.7倍，且為美國占世界出口額比率的三倍。 IMF另一項研究顯示，美國在整體貿易的占比下降，但美元貿易額占比未隨著同步減少。

The euro’s creators had hoped that it might supplant the dollar’s status. But even though almost half of trade is invoiced in euros, that is mostly because of how much trade involves countries that use the currency. Between 1999 and 2014 euro-denominated trade was only around 1.2 times the euro zone’s share of global imports.

歐元的創造者曾希望藉此取代美元的地位。但即使近半的貿易以歐元支付，這也大部分是因為使用歐元的國家涉及如此多的貿易。從1999年到2014年，以歐元計價的貿易僅是歐元區占全球進口額的1.2倍左右。

Other would-be challengers appear to have failed even more miserably. Scant Chinese data suggest that in 2013 only 17% of Chinese trade was settled in renminbi, and in 2012 only around half of such settlements were invoiced in renminbi. In order to avoid financial sanctions, Russia has recently shifted away from the dollar when paying for imports from China. But the euro, not the renminbi, benefited most.

其他可能的挑戰者似乎輸得更慘。寥寥無幾的中國數據顯示，2013年中國貿易僅17％用人民幣結算，而在2012年，此類結算只有大約一半是用人民幣支付的。俄羅斯為避免金融制裁，最近給付自中國進口的費用時已避免用美元。但是受益最大的是歐元，而非人民幣。

A lack of historical data makes it impossible to say whether Grassman’s Law held in the 1970s and has since weakened or whether it was the always an artefact of insufficient data. Whichever is true, economists busied themselves trying to work out why exporters used dominant currencies.

由於缺乏歷史數據，無法確定「格拉斯曼法則」究竟是只適用於1970年代，然後適用性減弱，還是該法則始終只是數據不足造成的假象。無論哪種說法為真，經濟學家還在忙著弄清楚，為什麼出口商使用主流貨幣。

One suggestion is that using the same vehicle currency when setting prices for a certain market lets companies avoid erratic price movements relative to their competitors. Ms Goldberg and Mr Tille offered some support for this when they showed that dollar invoicing was more common in markets, such as precious metals, where competition is cut-throat. Another suggestion is that the rise of global supply chains saw more exporters importing some inputs. Invoicing imports and exports in the same currency would preserve their profit margins in the event of a devaluation.

一個可能的解釋是，使用同一媒介貨幣在特定市場設定價格，公司相對於對手可避開不穩定的價格波動。戈柏和蒂爾提供了一些支持證據，如在貴金屬等競爭激烈的割喉市場中，美元支付更為普遍。另一個解釋是，全球供應鏈的興起，使更多出口商進口相同的原料。進出口貨物都以相同貨幣計價，萬一貨幣貶值，即可保住利潤。［對照這句原譯：如果進出口出現貶值，以相同貨幣支付將保住利潤。］

The arguments for a vehicle currency do not necessarily mean that that currency has to be the dollar. But why would it not be? The dollar already dominates the financial world. Central banks stash 58% of their official foreign-exchange reserves in it. It is the global currency of choice when issuing securities. Banks use it for around half of their cross-border claims. According to SWIFT, a payments system, it is used in two-fifths of international payments.

關於媒介貨幣的論點，並不一定意味著這貨幣必須是美元。但是為什麼不呢？美元已經主導金融世界，央行58％的官方外匯準備是美元，它是發行證券時的首選全球貨幣。也用於銀行大約一半的跨境索賠。根據付款系統SWIFT的說法，美元約用於五分之二的國際付款。

Indeed the worlds of finance and trade are intertwined. Exporters borrowing in dollars will want to price their foreign sales in the same currency, to protect against a sudden devaluation which would increase the value of their debt. Assets denominated in dollars offer their owners more security, because they will hold their value relative to imports priced in dollars.

事實上，金融和貿易世界是密不可分的。出口商借入美元，是想以相同貨幣對國外銷售進行定價，以防止突然貶值而債務增加。美元計價的資產為持有者提供更大的安全性，因為比起美元計價的進口產品更能保值。

Having established the importance of dollar dominance for global trade, economists updated their understanding of exchange-rate gyrations. In America sticky prices set in dollars mean the demand for imports is impervious to exchange-rate shocks. A Colombian light aircraft priced at $50,000 will cost the same when the dollar is worth 3,000 pesos as when it is worth 4,000. The change will eventually have an effect—but it will be partial, and slow. One study has found that two years after an exchange-rate shift only 44% of its effect would be seen in prices in America. Another found that just as prices did not change much, neither did the volumes importers chose to buy. After a 1% dollar depreciation, they found that the volume of imports into America fell by a measly 0.003%.

在確立美元主導地位對全球貿易的重要性後，經濟學家們更新對匯率波動的理解。在美國，價格緊黏著美元，意味著進口需求不受匯率衝擊的影響。一架定價50,000美元的哥倫比亞輕型飛機，不論美元匯價是兑3,000元披索或兑4,000元披索，售價都一樣。改變最終會產生影響，但將是局部且緩慢的。一項研究發現，匯率大幅變動兩年後，只有44％的影響會反映在美國物價上。另一個發現，一如價格沒有太大變化，進口商選擇購買的數量也沒多大影響。在美元貶值1％之後，他們發現，美國的進口量僅下降區區0.003％。

Money, money, money 錢錢錢

All this allows America to enjoy what Ms Gopinath describes as a “privileged insularity”. Its adjustment to a dollar depreciation happens almost entirely through exports, which immediately become cheaper in foreign markets. Devaluations against the dollar in other countries, by contrast, see them suffer. It becomes harder to afford imports while they don’t get the added export oomph the old models suggested. Exporters’ dollar earnings will be worth more in local currency, which might tempt some of them to expand. But that takes time. And the benefits are often offset by the higher cost of imported inputs.

所有這些使美國能夠享受戈皮納特所說的「特權的孤立」。美國對美元貶值的調整，幾乎全透過出口進行，而出口產品在外國市場立即變得便宜。相形之下，其他國家的貨幣對美元貶值，則使這些國家受苦。進口愈來愈難買得起，出口也未像舊模型所示那樣為之一振。出口商的美元收入以本地貨幣計價更值錢，這可能誘使其中一些業者擴大規模。但這需要時間，況且收益常被進口原料成本升高抵消。

Around the world invoicing imports in dollars means that it is devaluations against the greenback, rather than against the currency of the country you are trading with, that count. Emine Boz of the IMF, Ms Gopinath and Mikkel Plagborg-Muller of Princeton University found that prices of imported goods were relatively unresponsive to bilateral exchange-rate movements. 

Over short-term horizons they were six times more sensitive to the dollar exchange rate. The price of Brazilian-made football shirts in Mexico will stay the same if the peso depreciates relative to the real, but not relative to the dollar. If the peso drops with respect to the dollar, though, those shirts will become less affordable and may no longer be sold.

全球各地進口商品以美元計價，意味對美元貶值才茲事體大，對貿易對手國貨幣貶值並不要緊。 IMF的博茲（Emine Boz）、普林斯頓大學的戈皮納特（Gopinath）和馬勒（Mikkel Plagborg-Muller ）發現，進口物價對雙邊匯率變動相對沒有反應。短期內，它們對美元匯率的敏感性高六倍。如果披索對里爾貶值但未對美元貶值，墨西哥賣的巴西製足球衫價格將保持不變；但若披索對美元貶值，這些襯衫將變得更難買得起，甚至不再出售。

During the East Asian crisis of 1997-99 South Korea, Malaysia and Thailand all experienced currency depreciations of at least 60% relative to the dollar—and saw their export volumes stagnate or fall. With prices set in dollars devaluations did nothing for their export competitiveness within the region. And demand for imports from elsewhere in the region—also priced in dollars—plunged. Ms Boz and her co-authors have found that, after accounting for the business cycle, a 1% appreciation in the value of the dollar translates into a 0.6% decrease in the volume of trade between countries in the rest of the world.

在1997-99年的東亞金融風暴期間，南韓、馬來西亞和泰國的貨幣對美元至少貶值60％，而出口量不是停滯就是下降。以美元計物價下跌，對這些地區的出口競爭力毫無幫助，而從區內其他地方進口的需求（也以美元計價）也暴跌。博茲和她的合著者發現，在考量經濟周期之後，美元升值1％，意味著世界其他國家之間的貿易量下降0.6％。

Dollar dominance means trade is vulnerable to the global financial cycle, too. A study by Valentina Bruno and Hyun Song Shin of the Bank for International Settlements found that a dollar appreciation leads banks reliant on dollar funding to shrink their credit supply. Companies reliant on those banks—and their dollar-denominated financing of trade—then slow their exports, an effect particularly marked in companies with longer supply chains. Trade is a finance-hungry business.

美元支配地位意味著貿易也容易受全球金融周期的影響。國際清算銀行的布魯諾（Valentina Bruno）和申賢松（Hyun Song Shin）的研究發現，美元升值導致依賴美元資金的銀行縮減授信。依靠這些銀行取得美元計價貿易融資的公司，因此放慢出口腳步，這種影響在供應鏈較長的公司中尤其明顯。貿易是需要大量資金的業務。

Policymakers around the world yearn to be free of the dollar’s grip. That seems unlikely. The dollar’s dominance is the product of millions of individual decisions, each seemingly optimal, which in concert lead to collective problems. Each dip in the dollar’s value leads to a rush of wishful chatter about the dollar’s demise, but for long as these optimisations continue to make sense it is hard to see how that wish can come true. At least, though, for a while, the chatter-inducing weakness will provide a fillip to trade. ■

全球決策者渴望擺脫美元的束縛，這似乎不太可能。美元的主導地位是數以百萬計的個體決定下的產物，而每一個似乎都是最佳的決定，這些決定共同導致集體的問題。美元價值每下跌一次，都會引起人們一廂情願急著談論美元垮台，但只要這些最佳化措施仍有道理，就很難看出那種願望如何成真。至少有一段時間，引發議論紛紛的美元弱勢，將為交易提供興奮劑。 ■