銀行仍是全球經濟鏈條的薄弱環節

Why have the prices of bank shares fallen so sharply? A part of the answer is that stock markets have declined. Banks, however, remain the weak link in the chain, fragile themselves and able to generate fragility around them.

銀行股價格跌幅爲何如此之大？部分答案在於股市的整體下跌。然而，銀行仍然是整個經濟鏈條中的薄弱環節，它們本身很脆弱，同時可以把這種脆弱性傳導給周圍環節。

Between January 4 and February 15 2016, the Standard & Poor 500 index fell 7.5 per cent while the index of bank stocks fell 16.1 per cent. Over the same period, the FTSE Eurofirst 300 fell 9.5 per cent, while the index of bank stocks fell 19.5 per cent.

在2016年1月4日至2月15日期間，標準普爾500指數(Standard & Poor’s 500)下跌7.5%，而其銀行股指數下跌16.1%。同一時期，富時Eurofirst 300指數(FTSE Eurofirst 300)下跌9.5%，而其銀行股指數下跌19.5%。

The decline of European stocks was a little bigger than that of US ones but the underperformance of the European banking sector was similar. Relative to the overall US market, the index of shares in US banks fell 9.1 per cent, while that of European banks fell 11 per cent relative to European markets — and so only a bit more. (See charts.)

歐洲股市的跌幅稍大於美國股市，但是歐洲銀行業的表現同樣遜於美國銀行業。相對於整個美國股市，美國銀行股指數下跌9.1%，而歐洲銀行股相對歐洲股市跌幅爲11%——所以後者的跌幅只是略大一點。（見圖表）

The dire performance of European banks becomes more evident if one takes a longer view. Bank stocks have failed to recover the huge losses they suffered in the wake of the financial crisis of 2007-09. On February 15 2015, the S&P 500 was 23 per cent higher than on July 2 2007 but the US banking sector was still 51 per cent below where it had been then; the FTSE Eurofirst was 21 per cent below its 2007 level, reflecting the botched European recovery, but its banking sector was down by 71 per cent. In the European case a decline of 40 per cent in the value of bank stocks would return them to the 2009 nadir.

如果從更長期看，歐洲銀行股的慘淡表現會越發明顯。銀行股未能從2007-09年金融危機時的巨大跌幅中恢復。2015年2月15日，標普500指數比2007年7月2日高23%，但是美國銀行股指數仍比那時低51%；富時Eurofirst指數比2007年時的水平低21%，反映出歐洲糟糕的復甦情況，但是其銀行股指數比那時低71%。對歐洲而言，銀行股再下跌40%就回到2009年的谷底了。

So what might explain what is going on? The short answer is always: who knows? Mr Market is subject to huge mood swings. Yet a vital consideration, particularly in the US market, is that Robert Shiller’s cyclically adjusted price-earnings ratio is at levels substantially exceeded only in the stock market bubbles that peaked in 1929 and 2000. Investors might simply have realised that the downside risks to stocks outweigh the upside possibilities.

那麼怎樣解釋眼下的情況？簡短的回答總是一樣的：誰知道呢？市場先生受制於巨大的情緒波動。不過，有一個重要的考慮因素（特別是在美國股市）是，經週期因素調整後的“席勒市盈率”(Robert Shiller’s price-earnings ratio，又稱Shiller P/E)，只有在1929年和2000年股市泡沫達到巔峯時，才大幅高於現在的水平。投資者或許只是意識到了銀行股的下行風險大於上行的可能性。

Plausible worries could also have triggered such a realisation. Of such worries, there is no lack. One might be anxious about a slowdown in the American economy, partly driven by the strong dollar, weakening corporate profits and a misguided commitment to tightening by the US Federal Reserve. One might fear the short-term damage being done by collapsing commodity prices, which are imposing economic and fiscal stresses on commodity-exporting countries and financial pressures on commodity-producing companies. One might be concerned over the need for sovereign wealth funds to liquidate assets to fund fiscally stressed governments, particularly of the oil exporters. One might worry about a big slowdown in China and the ineffectiveness of its government’s policies. One might fear a new crisis in the eurozone. One might be worried about geopolitical risks, including the threat of war between Russia and Nato, disintegration of the EU and the chance that the next US president will be a hardline populist.

看似合理的擔憂也可能引發這樣的認識。這類擔憂從不缺乏。人們可能會擔心美國經濟放緩，後者部分由美元走強、企業利潤減少以及美聯儲錯誤地承諾收緊銀根造成。人們可能擔心大宗商品價格暴跌——對大宗商品出口國造成經濟和財政壓力、對大宗商品生產國造成金融壓力——帶來的短期傷害。人們可能擔心主權財富基金不得不變賣資產以向財政吃緊的政府（特別是石油出口國）提供資金。人們可能擔心中國經濟大幅放緩以及中國政府的政策不起作用。人們可能擔心歐元區爆發新危機。人們可能擔心地緣政治風險，其中包括俄羅斯和北約(Nato)爆發戰爭的威脅、歐盟解體以及下一任美國總統將會是強硬的民粹主義者的可能。

More fundamentally, chronic demand deficiency syndrome is worsening, with a slowing China adding to the sickness. It is possible to argue that a financial crisis is unlikely, without prior euphoria. One possible response is that it is the euphoria over China that is over. A better response, however, would be that the high-income economies have not yet recovered from the financial crisis and subsequent eurozone crisis, as ultra-low interest rates show.

更重要的是，慢性需求缺乏綜合徵正在惡化，中國經濟放緩可謂雪上加霜。可以認爲不太可能發生金融危機，但之前市場中的欣喜情緒已經消失。一種可能的回答是，對中國的欣喜之情已經結束。然而，更好的答案是高收入經濟體尚未從金融危機以及隨後的歐元區危機中恢復過來，正如超低利率所表明的那樣。

This array of worries, and particularly the ongoing deflationary pressure, throws a sharp light on the plight of the banks. Banks are highly leveraged plays on economies. If economies are sick, banks are likely to be sicker. Worse, the sicker the banks, the sicker will be economies. Worries about banks are shown now not only in the price of their stocks, but also dramatically so in the prices of contingent convertible bonds, or cocos . These bonds are hybrids: debt in good times but convertible into equity when common equity becomes too small relative to banks’ balance sheets. The collapse in the prices of cocos of a number of banks can be seen either as proof that they work or as the possible beginning of a death spiral, in which the signal of stress dries up the funding of fragile banks more broadly (see chart).

這一系列的擔憂——特別是眼下的通縮壓力——向銀行的困境投射了一道強光。銀行在經濟的基礎上有很高的槓桿。如果經濟病了，銀行可能會病得更重。更糟糕的是，銀行病得越重，經濟也會病得越重。如今，對銀行的擔憂不僅表現在它們的股價上，還極大地表現在應急可轉債(contingent convertible bonds)的價格上。這些債券都是混合型證券：行情好時是債券，但是當銀行的普通權益相對於銀行資產負債表過小時，可以轉化爲權益。許多銀行應急可轉債的價格崩盤，既可以被視爲它們在發揮作用、轉化爲權益的證據，也可能預示着死亡漩渦的開始，在這樣的漩渦裏，壓力信號在更大範圍上使脆弱的銀行資金枯竭（見圖表）。

Why should banks be so fragile after all the vaunted re-regulation? One answer is that they remain highly leveraged. If one ignores the vanishing trick of risk-weighting, the true leverage of many large banks remains at more than 20 to one. Another answer is that banks are exposed to almost everything. Poor market conditions undermine their returns from broking and wealth management.

在所有被大肆吹噓的再監管措施落實後，銀行爲什麼還會如此脆弱呢？其中一個答案是，它們仍然高度槓桿化。如果人們忽視風險權重這種消失把戲，很多大型銀行真正的槓桿仍然高於20比1。另一個答案是，銀行幾乎對一切資產都存在敞口。糟糕的市場環境破壞了銀行經紀和財富管理業務的收益。

The threat of deflation increases the likelihood of negative interest rates on reserves. The effect of that on the banks is uncertain but also worrying. At least as important is the flattening of the yield curve as returns on longer-term bonds collapse (see chart). A flat yield curve is bad for the profitability of banks, whose business is to borrow short and lend long. Commodity-price falls also raise worries about solvency of borrowers. A bigger issue is the new rules on resolution of banks in difficulty. These threaten creditors with forced conversions into equity. For shareholders, that would mean dilution. For creditors, it might mean unexpected losses.

通縮風險增加了存款準備金實行負利率的可能性。這對銀行的影響尚不確定，但是同樣令人擔憂。至少同樣重要的是，隨着較長期債券收益率驟降（見圖表），收益率曲線趨平。平坦的收益率曲線不利於銀行盈利，因爲銀行的業務是短借長貸。大宗商品價格下滑也引發了市場對借款人償債能力的擔憂。更重要的問題是對困境中銀行的處置新規。新規讓債權人面臨強制轉股的威脅。對於股東來說，這將意味着股權稀釋。對於債權人來說，這可能意味着意料之外的損失。

The world economy is not necessarily heading for a crisis, it is probably just heading for a slowdown — but risks abound. Moreover, such risks are bound to affect banks, particularly those of bank-dependent Europe. The weakened banks will then damage economies.

全球經濟並不一定會陷入危機，它可能只是在走向放緩——但是風險無處不在。此外，這類風險一定會影響銀行，特別是歐洲的銀行——歐洲經濟非常依賴銀行。然後，被削弱的銀行會損害經濟。

Policymakers must remain aware of these downside risks and do what they can to avoid adding to them. One thing remains clear: banks are still the weak links in the global economic chain. People worry about the health of these huge, highly leveraged, extremely complex and opaque behemoths. They are undoubtedly right to do so.

政策制定者必須對這些下行風險保持警惕，盡一切可能避免雪上加霜。有一點仍很明確：銀行仍然是全球經濟鏈條中的薄弱環節。人們擔心這些高槓杆、極爲複雜而且不透明的龐然大物的健康。他們的擔憂無疑是正確的。