Andy Warhol predicted that in the future everybody would be famous for 15 minutes. The Japanese are perfecting an even more egalitarian system under which everybody gets to spend 15 minutes as prime minister. Admittedly, it is still a work in progress. Naoto Kan has already clung on to the premiership for an unseemly three months. But with a little luck Ichiro Ozawa will defeat him in party elections later this month, edging Japan ever closer towards its 15-minute target.

To be serious for a moment, in the two decades since the bubble burst, Japan has had no fewer than 14 prime ministers, twice the number that Italy managed over the same period. Since Junichiro Koizumi quit in 2006, Japanese leaders have averaged fewer than 12 months in office apiece. Far from stabilising the situation, the Democratic Party of Japan, which took over a year ago, has put the cycle into an even faster spin. If Mr Ozawa wins on September 14, he will be Japan’s third prime minister in 12 months.

This Andy Warhol-style politics is hurting Japan in several ways. First, it is deeply unsettling for a population that has been told insistently that politicians are finally wresting power from Japan’s long-powerful bureaucrats. That was one of the themes of Mr Koizumi’s government. It is also an express aim of the Democratic party, which seeks to portray itself as a modern organisation responsive to public will. The public is entitled to ask: “Why on earth would we want these idiots in charge?”