警惕負利率變成零和遊戲 When negative rates become a zero sum game

Anyone hoping for a concerted effort to boost global growth will have been disappointed by the familiar combination of bland public conclusions and behind the scenes sniping at the G20 gathering in Shanghai. Policymakers committed to use all tools — monetary, fiscal and structural — to strengthen the recovery. But in reality, many are deferring difficult reforms and hoping that others will shoulder the burden of fiscal expansion. As for monetary policy, there is a clear concern that the latest weapon in central banks’ armoury — the adoption of negative interest rates — may amount to little more than a new way to wage an old-fashioned, beggar-thy-neighbour currency war.

每一個希望各國協同努力提振全球增長的人，都會對20國集團(G20)上海會議呈現出的令人熟悉的組合——即乏味的公開結論加暗地裏的相互詆譭——感到失望。政策制定者們承諾使用貨幣、財政和結構性政策等一切工具來強化復甦。但在現實中，許多國家卻拖延實施艱難的改革，寄望於由其他國家來肩負起財政擴張的重擔。至於貨幣政策，會議上存在一種明確的擔憂：央行武器庫裏的最新武器——負利率政策——或許不過是換了一種新的方式來發起老一套的“以鄰爲壑”的貨幣戰爭。

Mark Carney, the Bank of England governor, set out this concern most forcefully. It is critical for central banks to structure stimulus measures in ways that boost domestic demand, he argued, so that a “rising tide” of global demand could “lift all boats”.

英國央行(BoE)行長馬克慍尼（Mark Carney，見上圖）最爲犀利地闡述了這種擔憂。他主張，央行應以能夠增加內需的方式來構建刺激措施，這一點至關重要，因爲只有這樣全球需求“高漲的潮水”纔可以“托起所有的船隻”。

Negative interest rates are intended to achieve this, forcing banks to seek out riskier lending opportunities and assets, and encouraging consumers and borrowers to spend. It is plausible and technically possible for them to do so. However, many banks, and policymakers, are proving unwilling to make retail customers feel the full effects.

負利率政策的本意就是達成這一效果，迫使銀行尋求風險更高的放貸機會和資產，鼓勵消費者和借款者增加支出。這是合理的，在技術上也是有可行性的。然而，很多銀行和政策制定者並不情願讓零售客戶充分感受到負利率政策的影響。

Mr Carney therefore argues that there are limits to what the latest burst of innovation by central banks can achieve. If they craft policies in ways that shield retail customers, negative rates are unlikely to do much to stimulate domestic demand. Instead, the main effect will be on the exchange rate.

因此卡尼認爲，央行這輪創新能夠實現的效果是有限的。如果央行制定的政策繞開零售客戶，負利率就不太可能在刺激內需方面起到多大作用。相反，主要受影響的將是匯率。

This is attractive to the country concerned but it rapidly becomes a zero sum game, since “for monetary easing to work at a global level it cannot rely on simply moving scarce demand from one country to another”.

這對有關國家而言很有吸引力，但這會迅速演變成一種零和遊戲，因爲“要使貨幣寬鬆措施在全球層面起作用，就不能僅僅依賴於將稀缺的需求從一個國家轉移到另一個國家”。

This is a clear criticism of negative interest rates as they are practised in countries such as Japan, which adopted the policy in January but has kept paying interest on most bank reserves, allowing banks to keep rates positive for retail depositors. In the clubby world of central banking, such a forthright attack by Mr Carney on his peers is remarkable.

這是對多家央行實行的負利率政策的明確批評。日本央行從今年1月開始實行負利率政策，不過依然爲大部分的銀行存款準備金支付利率，這使銀行能夠繼續爲零售儲戶提供正利率。在央行這個小圈子裏，卡尼對同行們如此直言不諱的抨擊是非同尋常的。

His intervention is also important because the European Central Bank is considering adopting a similar tiered system, which might enable it to cut rates even further below zero without undermining confidence in the eurozone’s fragile banks.

而他出面發出干預也十分重要，因爲歐洲央行(ECB)也在考慮實行與日本類似的分級機制。這種機制或許能令該行將利率進一步下調到更大的負值，同時又不會降低人們對歐元區脆弱的銀行的信心。

The ECB faces a difficult choice. With the latest data showing that the eurozone has once more slipped into deflation, policymakers are under pressure to cut the deposit rate further into negative territory at this month’s meeting. If they leave lenders exposed to the full effects, they risk triggering a fresh sell off in banking shares. If they follow Japan’s lead and try to shield banks and retail depositors, they lay themselves open to accusations of currency wars.

歐洲央行面臨着艱難選擇。最新數據顯示歐元區已再次陷入通縮，在本月的會議上，政策制定者面臨將存款利率降到更大負值的壓力。如果他們讓銀行暴露於負利率政策的全面影響之下，可能會引發對銀行股的新一輪拋售。如果他們效仿日本的做法，試圖把銀行與零售儲戶保護起來，就會讓自身面臨發起貨幣戰爭的譴責。

Yet Mr Carney’s criticism is fair. His concerns are likely to be shared in the US, where policymakers are increasingly calling attention to the risks a stronger dollar poses to growth.

不過，卡尼的批評是公道的。美國可能會有人懷有同樣的顧慮。在美國，政策制定者們日益呼籲人們注意美元走強給增長帶來的風險。

It is also correct to warn that “at the global zero bound, there is no free lunch”. The surge in the value of the yen since the Bank of Japan’s move suggests that using negative rates as a tool for devaluation is at best an unreliable strategy. At worst, it risks reinforcing the impression that central bankers are acting out of desperation.

此外，“全球利率零下限環境下不存在免費午餐”的警告也是正確的。日本央行實行負利率政策以來日元匯率的飆升說明，把負利率作爲貶值工具，往好了說是一種不可靠的策略，往壞了說可能會加深央行的行動是出於絕望的印象。

Mr Carney contends it is a myth that central banks are “out of ammunition”. But he ends his speech with an admission that central bankers cannot restore the global economy to health without help from governments.

卡尼認爲，央行“用盡彈藥”的說法是無稽之談。不過，他在講話的末尾承認，若沒有來自政府的幫助，各國央行無法讓全球經濟恢復健康。