Like the bright lights in Tokyo’s Ginza shopping district, Japan has dazzled global investors this year. The Nikkei index is up almost 40 per cent and “Abenomics” – the economic policies of Shinzo Abe, prime minister – shows signs of working: economic growth has accelerated and, after two deflation-hit “lost decades”, consumer prices are rising, albeit on the back of higher imported energy costs.

In Tokyo it is easy to find optimists who believe Japan has found a way out of its economic paralysis. But visitors are also impressed by the scale of its monetary experiment, which has seen the Bank of Japan’s balance sheet expanding more relative to the size of the country’s economy than that of either the US Federal Reserve or European Central Bank. It is hard to escape concluding that the scope for market mishaps is large.

Currently, the big worry in Tokyo is that the US’s fiscal woes derail the global recovery. With its large-scale quantitative easing, which will double the monetary base within two years, the Bank of Japan has driven the yen sharply lower, helping exporters and raising import prices.