Lord Adair Turner, the chairman of the UK's financial regulator, not only caused a big stir this week when he suggested that there should be a global tax on banks. He also waded into a heated debate about government debt instruments, by coming out in favour of governments introducing a bond that would pay investors less at times of low economic growth.

At a wide-ranging roundtable published in the September issue of Prospect magazine, the Financial Services Authority chairman caused controversy when he said that a tax on financial transactions could be used as a tool to reduce bonus payouts at banks.