An investment of ￥1,000 in Japan’s Nikkei index would have grown to ￥1,270 over the past 30 years. Meanwhile, $1,000 invested in the US’s S&P 500 would now be worth $8,600. Visit both countries and you might be puzzled that the share price performance of companies could be so mediocre in one and so successful in the other. I am not advocating the state of a country’s public transport system as a reliable investment guide. But the efficiency and cleanliness of Narita airport and the trains into Tokyo contrast dramatically with the shambles of New York’s Newark airport and the city’s oft-vandalised subway.

The difference at least prompts me to question the current balance of market valuations. In the mid-1980s, when I began my career, Japan made up more than 40 per cent of the global index; today it is just 6 per cent. US equities made up 33 per cent; today it is 62 per cent. I was too inexperienced to suggest the index was unbalanced then. I am old enough to know that it might be today.

Over the years I have found that taking note of valuations can help steer you around trouble. Equities are generally valued according to their earnings (or cash flow) and growth potential. This can change swiftly during recessions, times of inflation and when interest rates rise.