Slightly more than a decade ago, I spent many hours at the Bank of Japan talking with officials about the paradoxes of ultra low rates. At the time, BoJ officials faced intense pressure from politicians and markets to boost growth; so they were duly implementing quantitative easing or their zero interest rate policy.

However, the more they experimented with Zirp, the more sceptical they seemed about whether it really worked. The essential problem, they moaned, was that Japan’s financial system was so broken that it had become bifurcated: some companies desperately needed cash, but could not borrow because the banks were too risk-averse to assume credit risk, with or without Zirp.

However, healthy companies that did not need loans were finding it laughably easy to raise money. The result was a classic liquidity trap. And, as such, it left men such as Masaru Hayami, then serving as BoJ governor, privately joking that he really ought to raise rates – not cut them – since that, at least, would make long-suffering savers happy.