【英语财经】汇率贬值并非万灵药 Dispiriting narrative that shows devaluation does not always work

The race to the bottom has begun. Confronted with disappointing growth rates, policy makers in some of the world’s largest economies are turning to currency devaluation in the hope this will trigger an export-led recovery.

First came Japan, with the yen falling by just over 20 per cent against the dollar since the central bank launched a turbocharged programme of asset purchases in April 2013. Then it was the turn of the eurozone. The euro has slumped by a similar amount during the past year on the back of the European Central Bank’s own easing moves. Even Beijing may have now quietly decided to weaken the renminbi, after letting it appreciate against the dollar in the second half of last year.

The rationale behind these moves is that a lower exchange rate should help to boost domestic producers in two ways. First, a devaluation will make imports more expensive, leading consumers to ditch foreign goods for products made at home. Second, a depreciation should cheapen the relative price of exports, helping companies to find new customers abroad.

“The net impact on the economy is an improvement in economic growth,” says Poonam Gupta of the World Bank. “This is borne out strongly in the empirical work” in economics, she adds.

The faith in the power of lower exchange rates clashes, however, with the experience of a number of rich

economies. During the financial crisis, sterling depreciated by more than 25 per cent against a basket of currencies.

Yet even this has failed to spur any improvement in Britain’s current account. Similarly, the sharp reduction in the value of the yen has done little to boost the performance of Japanese goods abroad.

One common explanation is that the UK and Japan were unlucky in the timing of their devaluation. Britain saw sterling plunge just as the eurozone, its main export market, entered a long recession. Similarly, Japan has weakened its currency at a time of slowing demand in Asia. Without a steep depreciation, so the argument goes, the performance of British and Japanese exports would have been even worse.

But there is an alternative and possibly more dispiriting narrative: as exporting companies become more productive and move into higher-quality segments of the market, their willingness to use a lower exchange rate to increase their market share abroad diminishes. Rather than seeking new customers by cutting prices, entrepreneurs may prefer to keep them unchanged, pocketing higher profits.

The evidence comes from a range of studies looking at the pricing behaviour of companies in Belgium, France and Argentina. Mary Amiti of the Federal Reserve of New York and her colleagues have shown the multinational corporations that dominate international trade are less likely to adjust prices in response to swings in the exchange rate.

This evidence is backed up by another study by Philippe Martin of Sciences Po in Paris, and others which looks at French exporters. “Larger and more productive companies do not decrease their prices by much in response to a devaluation,” Mr Martin said. “They will increase their mark-ups rather than their volumes,” he added.

Natalie Chen of Warwick university and Luciana Juvenal of the International Monetary Fund show companies producing high-quality goods are also reluctant to cut prices in the wake of devaluation. “If exchange-rate movements are more strongly absorbed into the export prices of higher quality goods?.?.?.?exchange-rate fluctuations have a less than proportional impact on aggregate trade prices and volumes,” they said.

These factors are not sufficient to wipe out the positive effects of a lower exchange rate. But they imply that countries that specialise in labour-intensive, lower-quality goods may have more to gain from cheapening their currency. For everyone else, the prize could well be smaller.

汇率贬值的竞赛已经开始。在遭遇令人失望的经济增长率之后，一些全球最大经济体的政策制定者诉诸于汇率贬值手段，寄望于这将激发出口拉动的经济复苏。

首先是日本，自日本央行在2013年4月推出庞大的资产购买计划以来，日元兑美元汇率下跌了20%以上。接下来是欧元区。由于欧洲央行(ECB)自己的宽松举措，欧元汇率在过去一年也下跌了差不多20%。甚至北京方面继去年下半年让人民币对美元升值之后，现在也可能悄悄决定让人民币贬值。

这些举动背后的逻辑是，货币贬值应该在两个方面有助于提振国内生产商。第一，贬值将让进口成本上升，从而导致消费者放弃外国商品，转而购买国产产品。第二，贬值应会让出口价格相对便宜，有助于公司在国外找到新的客户。

世界银行(World Bank)的普纳姆?古普塔(Poonam Gupta)表示：“汇率贬值对经济的净影响是经济增长改善。”她补充称，经济学上的“实证研究有力证明了这一点”。

然而，从许多富裕经济体的经历来看，人们不再相信汇率贬值的效力。在金融危机期间，英镑兑一篮子货币贬值逾25%。但即便这种贬值幅度也未能让英国的经常账户有所改善。同样，日元大幅贬值也几乎没有提振日本商品在海外的销售表现。

常见的解释是，英国和日本货币贬值的时机不太对。英镑大幅贬值之际，正值英国主要出口市场欧元区进入了漫长的衰退期。同样，日元贬值之际，正值亚洲需求放缓之际。这种观点认为，如果没有大幅贬值，英国和日本的出口表现甚至会更加糟糕。

但另一种可能更令人沮丧的说法是，随着出口公司产能提高并进入市场更高端领域，它们利用汇率贬值增加海外市场份额的意愿下降。企业家宁愿保持价格不变以赚取更高利润，也不愿通过降价寻求新的客户。

对比利时、法国和阿根廷公司的定价行为的一系列研究证明了这一点。纽约联储(Federal Reserve Bank of New York)的玛丽?阿米蒂(Mary Amiti)和同事们的研究表明，在国际贸易中占据主导地位的跨国企业不太可能针对汇率波动调整价格。

巴黎政治学院(Sciences-Po)的菲利普?马丁(Philippe Martin)开展的另一项研究，以及关于法国出口商的其他研究，也支持了这种观点。马丁表示：“面对汇率贬值，产能更高的较大型公司不会大幅降价。它们将会提高成本加价幅度，而非销量。”

华威大学(Warwick University)的Natalie Chen和国际货币基金组织(IMF)的卢恰娜?尤韦纳尔(Luciana Juvenal)的研究表明，生产优质产品的公司也不愿因为汇率贬值而降价。他们表示：“如果汇率波动得到较优质商品出口价格的更强吸收……汇率波动对总体贸易价格和规模的影响就会降低。”

这些因素不足以抹除汇率贬值的积极影响。但它们表明，专门生产劳动密集型、较低质量商品的国家可能从本币贬值中获得的好处更多。对其他所有国家来说，好处很可能没那么大。

译者/何黎