Hong Kong made what many consider to be the most successful example of direct government stock-market intervention in 1998, during the Asian financial crisis. The Hong Kong Monetary Authority acted swiftly and spent the equivalent of $15bn (€12bn, ￡10bn) on intervention – about 8 per cent of stock-market capitalisation. It made it clear it had enough reserves to continue intervening for as long as needed, and ended up making a profit.

Japan's problems this time round are different, however, and not everyone believes that this would be a magic cure for the ills affecting the stock market.

The idea was initially proposed this week by Japan's most powerful business lobby, the Keidanren. Kaoru Yosano, the new finance minister, said yesterday that it was being considered among measures.