During his eighteen-year tenure as chairman of the USA’s central bank, the Federal Reserve, Alan Greenspan was arguably the world’s most powerful public servant, and probably the most revered. This soft-spoken New Yorker – blue-suited and bespectacled like an older Clark Kent – came to be credited with an almost superhuman ability to calm or stimulate markets and hold the US economy on course for prosperity. His public statements, dense with obscure statistics and often deliberately ambiguous, were habitually hailed as pearls of sublime wisdom.

Although he never ‘abolished boom and bust’, as his friend Gordon Brown once claimed to have done, by the time he retired in 2006 he had achieved an unparalleled record of low inflation and relatively stable growth. America had been in recession for just 7 per cent of