Is Archbishop right to back Tobin tax?

Archbishop of Canterbury Dr Rowan Williams has backed the idea of a so-called 'Robin Hood Tax' on financial transactions, saying it would be a way of advancing the "moral agenda" of the protestors who have been camped outside St Paul's cathedral and in other cities across the world over the past few months. Campaigners for the Tobin Tax what a small levy imposed on share, bond and currency transactions to fund the "real economy".