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The Big Mac index

By The Economist
From The Economist
Published: February 06, 2013

Feb 2nd 2013 | Washington, DC |From the print edition

Currency wars: the burger's verdict.

AN OLD beef is again dividing the world of international finance: the spectre of "currency wars". Jens Weidmann, the head of Germany's Bundesbank, recently fretted that central-bank efforts to revive flagging economies could lead to an "increasing politicisation of exchange rates". Bill Gross of PIMCO, a huge bond-fund manager, reckons the world is entering a spiral of competitive devaluations reminiscent of the 1930s, as economies anxious for growth massage their currencies downward to give exporters a boost. What does burgernomics have to say?

The Big Mac index is The Economist's lighthearted analysis of foreign-exchange rates. Its secret sauce is the theory of purchasing-power parity (PPP), according to which prices and exchange rates should adjust over the long run, so that identical baskets of tradable goods cost the same across countries. Our basket contains only a Big Mac, and relies on the efforts of McDonald's to produce identical products from the same ingredients everywhere (or almost everywhere: for India we use the Maharaja Mac, which contains chicken rather than beef).

At market exchange rates, the Canadian version of the burger costs $5.39, compared with an average price of $4.37 in America. By our reckoning, then, the Canadian dollar is roughly 24% overvalued relative to its American counterpart. In Mexico, by contrast, a Big Mac is just $2.90 at market exchange rates, suggesting the peso is 33% below its long-run value relative to the dollar. The greenback buys much more Big Mac south of the border than north of it.

The Big Mac index suggests that currencies are particularly overvalued in Norway, Switzerland and Brazil (see chart). The continuing strength of the real is a big source of irritation to Brazil's finance minister, Guido Mantega, who first trumpeted the phrase "currency wars" in 2010. Brazil battled back by introducing capital controls in the form of taxes on foreign purchases of Brazilian securities, but the currency remains overvalued. In December Brazil notched a record current-account deficit as its exports tumbled, contributing to a slide in the economy's growth prospects. Switzerland handled its overcooked currency by pegging its franc to the euro in 2011. That halted the Swiss franc's appreciation against the then-beleaguered single currency, although not against the dollar.

Currencies in much of the emerging world, including Russia, China, and India, are too cheap relative to the dollar on our gauge. Critics of burgernomics say that you would expect average prices to be cheaper in poor countries than in rich ones because labour costs are lower: PPP signals where exchange rates should head over the long run, as a country like China gets richer, not where prices should be right now. Even so, the perennially undervalued yuan has scarcely moved towards the Big Mac measure of fair value. That, many reckon, is down to meddling by the chefs at the People's Bank of China, who are relying on export growth for sustenance: China posted a larger-than-expected $36.1 billion trade surplus in December, thanks to 14% growth in exports year-on-year.

Japan is the country that caused the most recent talk of currency battles. The new government's plan to reflate the economy with fiscal and monetary stimulus has helped drive the value of the yen down in recent months. The Big Mac index put the yen close to fair value against the dollar in July; it is more than 19% undervalued now. That's a tasty development for Japanese exporters but indigestible news for rivals.

Europeans are feeling particularly chippy. The euro is now around 12% too expensive relative to the dollar, according to our gauge; in the summer of 2012 it was close to fair value. The euro has strengthened in recent months as fears of a euro-area break-up have receded, but many Europeans also point the finger at currency manipulation. The European Central Bank has done little to boost an ailing euro-area economy even as other central banks, including the Federal Reserve and the Bank of England, have acted aggressively to add sauce to their economies. If the single currency keeps rising, euro-area exporters will end up in a pickle.

大麥克指數：日圓貶值沒道理

2013-02-06 天下雜誌 516期 作者：經濟學人

用各國的大麥克漢堡售價，來衡量匯率高低，結果顯示，日圓被嚴重低估一九％，顯然還有升值空間；歐元則被高估一二％，出口競爭力大傷。

最近，日本挑起了不少爭端。

釣魚台危機尚未化解。新上任的首相安倍晉三，為了復甦經濟，推動貨幣寬鬆政策。日圓走貶，全球貨幣大戰，開了第一槍。

經濟學家如熱鍋上的螞蟻。德國央行總裁魏德曼指出，中央銀行救經濟，「導致匯率更加政治化。」

太平洋投資管理公司的債券基金天王葛洛斯則警告說，目前惡性競貶的狀態，有如一九三○年代大蕭條的徵兆。

那麼，「大麥克指數」（Big Mac index）的看法如何？

大麥克指數，是《經濟學人》衡量匯率的獨門量表。世界各處都有麥當勞，《經濟學人》用大麥克漢堡（即台灣的麥香堡）的當地售價，衡量各國貨幣兌換美元的匯率，是過高或過低。

扮演導火線的日圓，去年七月的匯率還算合理。如今低估超過一九％，成為最被低估的主要貨幣。

日本的出口商，應該樂透了。但是競爭對手可就倒大楣。

許多新興國家，如中國、印度和俄國，也是貨幣被嚴重低估。中國經濟快速成長，人民幣的價值卻沒有提升。結果就是，十二月，中國的貿易順差高達三六一億美元，每年出口成長一四％。

金磚四國當中，只有巴西的雷亞爾，跟挪威、瑞士的貨幣一樣，持續地被高估。發明「貨幣戰爭」一詞的巴西財政部長曼蒂加，特別為此感到頭痛。

巴西的反擊，是對外資課稅。可惜效果不彰。十二月，巴西的貿易順差創下十年新低，重創國內經濟。

瑞士的對策，則是在一一年，將瑞士法郎跟歐元掛鉤。但是，跟美元比起來，還是處於被高估的狀況。

在美洲，加幣被高估二四％，墨西哥披索被低估三三％。

最有意思的是，大西洋對岸的歐元。

去年夏天，歐元的匯率很公平。現在，它被高估一二％。歐洲人埋怨說，都是外國的貨幣寬鬆政策在作祟。美國聯邦銀行、英國央行，都為國內經濟著想，讓貨幣走低。

相較之下，歐洲央行可說是坐以待斃。如果歐元持續被高估，歐盟難保出口競爭力，將導致經濟惡化。（周原譯）