Bill Gates explains his support for a Tobin tax
2 November 2011 Last updated at 23:29 GMT
Microsoft founder Bill Gates has spoken to the BBC about his backing of a tax on financial transactions.
Mr Gates is to submit a report to the G20 group of advanced and emerging economies at a two-day summit in Cannes.
The Archbishop of Canterbury, Dr Rowan Williams, has also supported calls for a tax on financial transactions, the so-called Tobin tax.