In less than two years, negative interest rates have moved from the abstract realms of economic theory into the mainstream of monetary policymaking. The experiment under way in the eurozone, Japan and some smaller European economies has shown that the practical obstacles to taking rates below zero are not as large as once imagined. Proponents say the policy — intended to encourage consumers to spend and banks to lend more to the real economy — has saved the eurozone from sinking into disastrous deflation. But the evidence for this remains tentative. Meanwhile, negative rates are undeniably unpopular, and the longer they remain in place the greater the risk of unintended consequences.

还不到两年，负利率就从抽象的经济理论领域进入了货币政策制定的主流。欧元区、日本和欧洲更小经济体正在进行的实验已表明，把利率压低至负数的实际障碍，没有人们之前想象的那么大。支持者表示，该政策——旨在鼓励消费者花钱、鼓励银行向实体经济发放更多贷款——已拯救了欧元区，使之没有跌入灾难性通缩。但仍没有决定性证据能够证明这一点。另一方面，负利率无疑是不受欢迎的，负利率执行时间越长，带来意外后果的风险也越大。

The latest attack on the policy comes from Larry Fink, head of the asset manager BlackRock, who warns of the toll that low, and now negative, rates are taking on savers. People who want a certain income at retirement must now invest far more to achieve it and cut spending accordingly, he argues — making the policy counterproductive.

负利率政策受到的最新批评，来自资产管理公司贝莱德(BlackRock)的掌门人拉里•芬克(Larry Fink，见上图)。芬克对很低、目前进入负区间的利率对储户造成的危害提出了警告。他辩称，希望让退休后的收入达到一定数额的人，现在必须投资更多才能拿到那个数额，并必须相应地减少消费，这恰恰与负利率政策期望的效果相反。

This could be said of any cut in interest rates, which will always shift income from savers to borrowers. The burden on savers need not outweigh the boost to borrowers simply because interest rates have crossed a psychological threshold at zero.

可以说，每一次降息都有这样的效果。降息时，收益总是从储户流向借款者。降息加在储户身上的负担，未必会仅因为利率跨过了零的心理关口，就超过降息对借款者的提振。

Nonetheless, José Viñals, a senior IMF official, has warned that negative rates could become more damaging for society the longer they persist, undermining the viability of life insurers, pensions and savings vehicles.

然而，国际货币基金组织(IMF)高级官员何塞•比尼亚尔斯(José Viñals)警告称，负利率持续时间越长，可能对社会构成的危害就越大，破坏寿险公司、养老金和储蓄工具的存续能力。

Savers’ anger is already a very real political constraint on cutting rates further. In Japan, the central bank has attempted to shield retail deposits from the full effect of negative rates, but some banks are now set to impose charges on cash they hold for pension funds. In Germany, the issue of pensioner poverty is so explosive that Wolfgang Schäuble has blamed the rise of populist political parties on European Central Bank policies.

储户的愤怒在政治上已经对央行进一步降息构成非常切实的约束。在日本，央行已采取措施减轻负利率对零售储蓄的冲击，但现在，有些银行已确定要对自己替养老基金持有的资金收费。在德国，退休老人的贫困问题争议性非常大，乃至财长沃尔夫冈•朔伊布勒(Wolfgang Schäuble)把民粹主义政党的崛起归咎于欧洲央行(ECB)的政策。

A bigger concern for eurozone policymakers has been the effect of negative interest rates on an already fragile banking sector. Institutions that are unable to increase lending or to pass the costs of negative rates on to their depositors face a squeeze on profits. For all banks, there is an incentive to rely more on cheaper, but more volatile, wholesale funding.

令欧元区政策制定者更为担心的问题，是负利率对本已脆弱的银行业的冲击。那些无法加大放贷或把负利率成本转嫁给储户的银行，其利润会遭到挤压。所有银行都有动力更多地依赖成本更低、但更不稳定的批发资金。

Despite these concerns, many central bankers contend that the overall effect of negative rates has been positive. Wholesale interest rates have fallen, and credit growth in the eurozone has picked up since their introduction. For smaller economies, the policy has also helped to limit capital inflows and stem currency appreciation — despite the notable and counterintuitive rise in the euro and yen.

尽管存在这些担忧，许多央行仍辩称，负利率的总体效果是积极的。批发利率已下降，自负利率被引入以来，欧元区的信贷增长有所加快。对更小的经济体而言，负利率政策也帮助限制了资本流入并阻止本币升值——尽管欧元和日元出现了违反常理的显著升值。

Ben Bernanke, the former Federal Reserve chair, judges that anxiety has been overdone and that the policy has “modest benefits and manageable costs”. It could be a useful tool for the Fed if US policymakers want to ease without “rolling out the big QE gun”.

美联储(Fed)前主席本•伯南克(Ben Bernanke)认为，人们的担忧有些过头了，负利率政策“具有一定的好处和可控的代价”。如果美国政策制定者希望在不“使出量化宽松(QE)大招”的情况下实现宽松，那么负利率对美联储而言可能会是一个有用的工具。

Yet there are clear practical limits to cutting rates indefinitely; and in the eurozone at least, the policy may be close to its political limits. The question now is what should take its place. Mr Fink is right to say that the current anomalies in markets are the result of central banks being asked to solve economic problems in the absence of coherent fiscal policies.

不过，无限降息存在明显的实际限制；至少在欧元区，降息政策在政治上或许已接近极限。目前的问题在于，应该用何种政策来取代降息。芬克表示，央行在缺乏财政政策配合的情况下被要求去解决经济问题，才导致了当前市场的异常状况。这话没错。

The underlying challenge is how to strengthen stimulus policies and make them more effective. “Nein zu Allem” — as Mario Draghi caricatured Germany’s position — is not an acceptable answer. Opponents of negative rates need to spell out the alternatives.

根本挑战在于如何强化刺激政策，让政策更加有效。“对一切都说不(Nein zu Allem)”——这是马里奥•德拉吉(Mario Draghi)对于德国立场的夸张性描述——不是一个令人满意的答案。负利率政策的反对者需要拿出可以替代它的选项。