文章来源：《经济学人》Mar 18th 2023 期 Leaders 栏目 What's wrong with the banks

Only ten days ago you might have thought that the banks had been fixed after the nightmare of the financial crisis in 2007-09. Now it is clear that they still have the power to cause a heart-stopping scare. A ferocious run at Silicon Valley Bank on March 9th saw $42bn in deposits flee in a day. svb was just one of three American lenders to collapse in the space of a week. Regulators worked frantically over the weekend to devise a rescue. Even so, customers are asking once again if their money is safe.

仅仅在十天前，你可能还认为银行在经历了2007-2009年金融危机的噩梦之后已经得到了修复。现在很明显，它们仍然有能力制造令人心悸的恐慌。3月9日，硅谷银行发生了一场惨烈的挤兑，一天之内就有420亿美元的存款“外逃”。SVB只是一周内倒闭的三家美国银行之一。整个周末，监管机构都在疯狂地工作，以试图设计出一套纾困方案。即便如此，客户们还是一再质疑他们的钱是否安全。

Investors have taken fright. Fully $229bn has been wiped off the market value of America’s banks so far this month, a fall of 17%. Treasury yields have tumbled and markets now reckon the Federal Reserve will begin cutting interest rates in the summer. Share prices of banks in Europe and Japan have plunged, too. Credit Suisse, which faces other woes, saw its stock fall by 24% on March 15th and on March 16th it sought liquidity support from the Swiss central bank. Fourteen years since the financial crisis, questions are once again swirling about how fragile banks are, and whether regulators have been caught out.

投资者已经感到恐慌。本月到目前为止，美国银行的市值已经蒸发了2290亿美元，跌幅达到17%。美国国债收益率已经大幅下跌，市场现在预计美联储将在夏季开始降息。欧洲和日本银行的股价也大幅下跌。面临其他困境的瑞士信贷，其股价在3月15日下跌了24%，并于3月16日向瑞士央行寻求流动性支持。自金融危机爆发以来已经过去了14年，人们再次质疑银行的脆弱程度以及监管机构是否被欺骗。

The high-speed collapse of svb has cast light on an underappreciated risk within the system. When interest rates were low and asset prices high the Californian bank loaded up on long-term bonds. Then the Fed raised rates at its sharpest pace in four decades, bond prices plunged and the bank was left with huge losses. America’s capital rules do not require most banks to account for the falling price of bonds they plan to hold until they mature. Only very large banks must mark to market all of their bonds that are available to trade. But, as svb discovered, if a bank wobbles and must sell bonds, unrecognised losses become real.

SVB的快速倒闭揭示了该体系中一个被低估的风险。在利率低、资产价格高的时候，这家加州的银行大量买入长期债券。随后，美联储以40年来最快的速度加息，债券价格暴跌，银行遭受了巨大损失。美国的资本规则并不要求大多数银行对他们计划持有直至到期的债券价格下跌作出解释。只有非常大的银行才必须将其所有可交易的债券按市价计价。但是，正如SVB所发现的那样，如果一家银行“波动”，必须出售债券，未确认的损失就会成为真实损失。

Across America’s banking system, these unrecognised losses are vast: $620bn at the end of 2022, equivalent to about a third of the combined capital cushions of America’s banks. Fortunately, other banks are much further away from the brink than svb was. But rising interest rates have left the system vulnerable.

在整个美国银行体系中，这些未确认的损失是巨大的: 到2022年底，损失为6200亿美元，相当于美国各银行缓冲资本总额的三分之一左右。幸运的是，与SVB相比，其他银行离破产的边缘要远得多。但不断上升的利率使体系变得脆弱。

The financial crisis of 2007-09 was the result of reckless lending and a housing bust. Post-crisis regulations therefore sought to limit credit risk and ensure that banks hold assets that will reliably have buyers. They encouraged banks to buy government bonds: nobody, after all, is more creditworthy than Uncle Sam and nothing is easier to sell in a crisis than Treasuries.

2007-2009年的金融危机是不计后果的放贷和房地产泡沫破裂的结果。因此，危机后的监管试图限制信贷风险，并确保银行持有可靠的有买家的资产。他们鼓励银行购买政府债券: 毕竟，没有人比"山姆大叔"更有信誉，在危机中没有什么比国债更容易出售。

Many years of low inflation and interest rates meant that few considered how the banks would suffer if the world changed and longer-term bonds fell in value. This vulnerability only worsened during the pandemic, as deposits flooded into banks and the Fed’s stimulus pumped cash into the system. Many banks used the deposits to buy long-term bonds and government-guaranteed mortgage-backed securities.

多年的低通胀和低利率意味着，很少有人考虑到，如果世界发生变化，长期债券价值下跌，银行将遭受怎样的损失。这种脆弱性在疫情期间进一步恶化，因为存款大量涌入银行，美联储的刺激措施向金融体系注入了大量现金。许多银行用这些存款购买长期债券和政府担保的抵押贷款支持证券。

You might think that unrealised losses don’t matter. One problem is that the bank has bought the bond with someone else’s money, usually a deposit. Holding a bond to maturity requires matching it with deposits and as rates rise, competition for deposits increases. At the largest banks, like JPMorgan Chase or Bank of America, customers are sticky so rising rates tend to boost their earnings, thanks to floating-rate loans. By contrast, the roughly 4,700 small and mid-sized banks with total assets of $10.5trn have to pay depositors more to stop them taking out their money. That squeezes their margins—which helps explain why some banks’ stock prices have plunged.

你可能认为未变现亏损无关紧要。其中一个问题是，银行用别人的钱(通常是存款)购买了债券。持有到期债券需要与存款相匹配，随着利率上升，对存款的竞争也会加剧。在摩根大通或美国银行等大型银行，客户具有粘性，因此利率上升往往会提高他们的收入，这要归功于浮动利率贷款。相比之下，总资产约为10.5万亿美元的约4700家中小银行必须向储户支付更多费用，以阻止他们取出存款。这就挤压了银行的利润——这也解释了为什么一些银行的股价暴跌。

The other problem affects banks of all sizes. In a crisis once-loyal depositors could flee, forcing the bank to cover deposit outflows by selling assets. If so, the bank’s losses would crystallise. Its capital cushion might look comforting today, but most of its stuffing would suddenly become an accounting fiction.

另一个问题影响着各种规模的银行。在危机中，曾经忠诚的储户可能会逃离，迫使银行通过出售资产来弥补存款外逃。如果是这样，银行的损失将会“具体化”。它的资本缓冲在今天看起来可能令人欣慰，但它的大部分内容会突然变成会计虚构。

That alarming prospect explains why the Fed acted so dramatically last weekend. Since March 12th it has stood ready to make loans secured against banks’ bonds. Whereas it used to impose a haircut on the value of the collateral, it will now offer loans up to the bonds’ face value. With some long-term bonds, this can be more than 50% above market value. Given such largesse, it is all but impossible for the unrealised losses on a bank’s bonds to cause a collapse. And that means that the bank’s depositors have no reason to start a run.

这一令人担忧的前景解释了美联储为何在上周末采取了如此戏剧性的行动。自3月12日以来，它已准备好以银行债券为抵押发放贷款。尽管它过去对抵押品的价值进行了扣减，但现在它将提供债券面值相当的贷款。对于一些长期债券，这可能比市场价值高出50%以上。鉴于其如此慷慨，银行债券的未变现损失几乎不可能导致破产。这意味着银行的储户没有理由开始挤兑。

The Fed is right to lend against good collateral to stop runs. But such easy terms carry a cost. By creating the expectation that the Fed will assume interest-rate risks in a crisis, they encourage banks to behave recklessly. The emergency programme is supposed to last only for a year but, even after it has expired, banks competing for deposits will search for high returns by taking excessive risks. Some depositors, knowing that the Fed has stepped in once, will not have much reason to discriminate between good risks and bad.

美联储以优质抵押品为抵押发放贷款以阻止挤兑的做法是正确的。但如此简单的条款是有代价的。通过制造美联储将在危机中承担利率风险的预期，他们鼓励银行不计后果地行事。该紧急计划本应只持续一年，但即使在该计划到期后，争夺存款的银行仍将通过过度冒险来寻求高回报。一些存款人知道美联储已经介入过一次，他们没有太多理由区分好的风险和不良风险。

Regulators must therefore use the year ahead to make the system safer. One step is to remove many of the odd exemptions that apply to mid-sized banks, some of which were the result of post-crisis rules being rolled back amid much lobbying in 2018 and 2019. The rescue of depositors in svb demonstrates that policymakers think such banks pose systemic risks. If so, they should face the same accounting and liquidity rules as the megabanks—as they do in Europe—and be required to submit to the Fed plans for their orderly resolution if they fail. In effect, this would force them to increase their safety buffers.

因此，监管机构必须利用未来一年的时间让金融体系更加安全。其中一个步骤是取消许多适用于中型银行的奇怪豁免，其中一些是在2018年和2019年的大量游说中取消危机后规则的结果。对SVB储户的救助表明，政策制定者认为此类银行构成系统性风险。如果是这样的话，它们就应该像大型银行一样，面对同样的会计和流动性规则（就像它们在欧洲所面临的那样），如果它们破产，就必须向美联储提交有序的解决方案。实际上，这将迫使它们增加安全缓冲。

Regulators everywhere must also build a regime that recognises the risks from rising interest rates. A bank with unrealised losses will be at greater risk of failure during a crisis than one without such losses. Yet this disparity is not reflected in capital requirements. One idea is to stress-test what might happen to a bank’s safety cushion were its bond portfolios marked to market, and if rates rose further. Policymakers could then consider whether on this measure the system has enough capital.

各地的监管机构还必须建立一种认识到利率上升风险的机制。在危机中，有未实现亏损的银行比没有此类亏损的银行倒闭的风险更大。然而，这种差异并没有反映在资本要求上。其中一个想法是，对一家银行的债券投资组合按市价计价以及利率进一步上升时，其安全缓冲可能发生的情况进行压力测试。然后，政策制定者可以考虑在这一衡量标准上，银行体系是否拥有足够的资本。

Bankers will hate the idea of yet more capital buffers and rulemaking. But the gains from safety are vast. Depositors and taxpayers from Silicon Valley to Switzerland are facing a mighty scare. They should not have to live with the fear and fragility they thought had been consigned to history years ago.

银行家们会讨厌更多的资本缓冲和规则制定的想法。但安全带来的好处是巨大的。从硅谷到瑞士，储户和纳税人都面临着巨大的恐慌。他们不应该生活在恐惧和脆弱中，他们认为这种恐惧和脆弱早在几年前就已成为历史。