【背景】周三公布的數據顯示，日本央行1月份購買了創(chuàng)數據紀錄的23.69萬億日元(約合1820億美元)的國債，突顯出該行捍衛(wèi)收益率上限的決心，以讓其不受押注’央行會在短期內加息‘的投資者的攻擊。去年12月，日本央行決定擴大圍繞10年期國債收益率目標設定的區(qū)間，這加劇了市場對它將在近期加息的預期，并迫使日本央行加大債券購買力度，以捍衛(wèi)新設定的10年期國債收益率0.5%的上限。

Changing the helmsman halfway through a tricky manoeuvre at sea is a risky prospect. Yet that is what is happening in Japan, where the government will soon propose a successor to Kuroda Haruhiko as the head of the Bank of Japan, just as the central bank prepares to tighten monetary policy for the first time since 2007. In December, amid rising inflation and speculative pressure, the bank raised its cap on ten-year government-bond yields, from 0.25% to 0.5%. The next governor is expected to raise the cap further, or even to abandon the policy, which is known as yield-curve control.

【背景】"收緊貨幣政策"也稱緊縮的貨幣政策，是指央行收緊市場上貨幣的供應量，使市場資金利率提升的行為。貨幣政策收緊是為了防止經濟過熱出現(xiàn)泡沫，防止出現(xiàn)物價大幅上漲通貨膨脹，使得市場上貨幣的總需求和總供給趨于均衡。此外貨幣政策緊縮還會影響資本市場，使股票等資本市場短期出現(xiàn)下跌?！?/span>

在海上進行一次棘手的操作時，中途更換舵手是一種危險的前景。然而，這正是日本正在發(fā)生的事情。在日本央行準備收緊貨幣政策（2007年以來第一次）之際，日本政府將很快提名一位接替黑田東彥出任日本央行行長的人選。去年12月，在不斷上升的通貨膨脹和投機壓力下，央行將十年期政府債券收益率上限從0.25%提高到0.5%。預計下任行長將進一步提高上限，甚至放棄這種被稱為"收益率曲線控制"的政策。

Unfortunately, the regime change is not off to a good start. Lifting the cap has only increased bets against it. Since December the Bank of Japan has had to defend the higher cap by buying bonds worth a staggering $240bn, nearly 6% of Japan’s gdp and about three times the pace of purchases in the preceding three months. The bank seems determined to keep the cap in place until a change of leadership is complete. Doing so is a costly mistake. It should change course now.

不幸的是，"管理體制"更迭的開端并不好。取消上限只會增加對它的押注。自去年12月以來，日本央行不得不通過購買價值驚人的2400億美元的債券來捍衛(wèi)更高的上限，這一金額幾乎是日本GDP的6%，大約是前三個月購買速度的三倍。該央行似乎決心在領導層換屆完成之前保持這一上限。這樣做是錯誤的，而且代價高昂。它應該現(xiàn)在改變路線。

Yield-curve control has been the most awkward part of the monetary-policy toolkit developed after the global financial crisis of 2007-09. Having run out of space to cut short-term interest rates, central banks tried to drive down long-term bond yields instead. To that end, they bought bonds with newly created money. By 2016, however, the Bank of Japan’s balance-sheet was ballooning, and it introduced a yield cap in the hope of keeping yields low while making fewer purchases. The idea was that yields would adjust purely on the expectation that the central bank would act if necessary to enforce the cap. And for a time, the policy worked as intended.

在2007-2009年全球金融危機之后，收益率曲線控制一直是貨幣政策工具箱中最棘手的部分。由于削減短期利率的空間已經用盡，各國央行轉而試圖壓低長期債券收益率。為此，他們用新發(fā)行的貨幣購買債券。然而，到2016年，日本央行的資產負債表急劇膨脹，它引入了收益率上限，希望在減少購買的同時保持低收益率。當時的想法是，收益率將純粹根據央行在必要時采取行動實施上限的預期進行調整。在一段時間內，該政策起到了預期的效果。

As inflation has risen, however, such caps have lost their credibility. In 2021 Australia suddenly abandoned its experiment with yield-curve control as investors began betting that interest rates would need to rise to fight inflation.

然而，隨著通貨膨脹的上升，這種上限已經失去了可信度。2021年，澳大利亞突然放棄了其收益率曲線控制的嘗試，因為投資者開始押注利率將需要上調以對抗通脹。

In Japan the situation is more finely poised, because inflation has been too low for decades and ongoing stimulus may be necessary to ensure the Bank of Japan hits its 2% inflation target over the next few years. But Japan’s policy is far more aggressive than Australia’s, which capped bonds at a three-year, rather than a ten-year, horizon. A small change in the outlook for the next decade is enough to bring a ten-year cap under pressure.

日本的情況更為穩(wěn)定，因為幾十年來通脹一直過低，為了確保日本央行在未來幾年達到2%的通脹目標，持續(xù)的刺激措施可能是必要的。但日本的政策遠比澳大利亞激進，澳大利亞將債券期限限制在3年期，而非10年期。未來十年前景的一個小變化就足以使十年上限面臨壓力。

Investors know that Mr Kuroda’s successor is likely to adjust and eventually abandon the policy—especially if it is a hawk, such as Yamaguchi Hirohide, a former deputy governor. The result has been rampant speculation, forcing the bank to hoover up more bonds: exactly what yield-curve control was supposed to avoid. The bank now owns more than half the Japanese government-bond market, including two-thirds of bonds with a maturity between one and 11 years. Bizarrely, its accounts imply that it owns more than 100% of the issuance of some bonds, having lent out its purchases only to buy them back again.

投資者知道黑田東彥的繼任者很可能會調整并最終放棄該政策——尤其是如果繼任者是鷹派，比如前副行長山口廣秀。其結果是投機活動猖獗，迫使銀行吸收更多債券: 這正是收益率曲線控制應該避免的。日本央行目前持有日本政府債券市場一半以上的份額，其中三分之二的債券期限在1年至11年之間。奇怪的是，它的賬目表明它擁有部分債券發(fā)行量的100%以上，借出所購買的債券只是為了再買回來。

For investors, selling bonds to the bank seems a one-way bet. Yields move inversely to prices. Why own a bond that will fall in value as the cap is lifted, if you can sell it for a higher price today? But for the Bank of Japan the purchases could prove correspondingly costly. We calculate that a rise in bond yields of just 0.25 percentage points would cause paper losses of over $60bn. The bank’s cash flows will suffer if short-term rates rise before the bonds mature, forcing the bank to pay interest on the reserves it has created in the banking system to finance its purchases. With every bond bought, the potential loss mounts.

對投資者來說，向該行出售債券似乎是一種單向押注。收益率與價格成反比。如果你現(xiàn)在就能以更高的價格出售，為什么還要持有隨著上限取消而貶值的債券呢? 但對日本央行來說，購買債券的代價可能會相應很高。根據我們的計算，債券收益率僅上升0.25個百分點，就會造成逾600億美元的賬面損失。如果短期利率在債券到期前上升，銀行的現(xiàn)金流將受到影響，這將迫使銀行為購買債券而在銀行體系中創(chuàng)造的準備金支付利息。每購買一筆債券，潛在的損失就會增加。

Some argue that the yield cap must be maintained until after wage negotiations in the spring, so that it stimulates average pay rises high enough to be consistent with price growth of 2%, ensuring Japan’s escape from decades of low inflation. But the limited extra stimulus brought about by the cap is not worth the possible losses, which pose a threat to taxpayers. Instead, the central bank’s most important tool is its short-term interest rate, which it can still pledge to keep low to act as a stimulus.

一些人認為，收益率上限必須維持到春季工資談判結束后，以便刺激平均工資增長，使其足以與2% 的物價增長保持一致，確保日本擺脫數十年的低通脹。但是，上限帶來的有限的額外刺激抵不了可能的損失，這對納稅人構成了威脅。相反，央行最重要的工具是其短期利率，它仍然可以承諾維持在低位，以起到刺激作用。

Signalling the end of a price peg is unwise, because it attracts speculation and forces a messy exit. It is too late to avoid that. Everyone knows that the end of yield-curve control is coming in Japan. The central bank—whoever is at its helm—can at least kill off the policy before it loses a lot more money.

發(fā)出結束釘住價格的信號是不明智的，因為這會吸引投機，并迫使混亂的退出?，F(xiàn)在要避免已經太晚了。每個人都知道，收益率曲線控制在日本即將結束。日本銀行——不管是誰掌舵——至少可以在它損失更多的錢之前終止這項政策。