The Bank of Japan should stop defending its cap on bond yields

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. 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 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.