In all the excitement about Japan’s rediscovery of its long-lost mojo, one question has largely gone unasked. What made the country’s establishment change tack so suddenly? One minute, the powers that be thought there was nothing much that could be done about deflation. The next, everyone had rallied around Shinzo Abe, the new prime minister, and his mission to reverse 15 years of falling prices.

So dramatic has been the shift in policy – and so rapidly have markets responded – that everyone has been too busy making money to worry much about what triggered the change. The yen has weakened from Y77 to the dollar to nearly Y100, benefiting exporters. The broad Topix index is up 65 per cent in six months, the strongest rally in decades. Stock market gains have added Y150tn, or nearly $1.5tn, to the market capitalisation of Japanese companies, says Peter Tasker, an analyst at Arcus Research. So grateful are investors for the bonanza, he jokes, that they now customarily sign off their emails: “All hail to Abe.”

Market excitement is beginning to rub off on the real economy. That supports those who contend that springing the deflationary trap can produce a self-perpetuating cycle in which profits, wages, consumer spending and taxes float higher. Toyota, which tripled its net profits to nearly $10bn in the year to March, said on Wednesday that it expected profits to increase by another 40 per cent this year. Earnings at Nomura and Daiwa have surged as the brokerages benefit from the new risk appetite among Japanese investors. In March, sales at large retailers posted their biggest gains in 20 years. Even wages at some companies have begun to edge up amid signs of a tightening labour market. The central bank is now predicting economic growth for this year of a not-too-shabby 2.9 per cent.