A taboo in polite circles until recenty, the so-called Tobin Tax has recently been advocated by Gordon Brown

Critical theories are theories that more or less comprehensively challenge the existing social order. The criticisms they formulate do not concern particular aspects of this order, like the imposition of a tax on financial transactions (the ‘Tobin tax’) or some measure relating to pension reform

Capital controls are taxes, and differ from exchange controls. The latter place limits on the amount of a nation’s currency that can be taken abroad. Instead, the financial transaction tax or Tobin tax is a form of capital control, a tax on and ‘sand in the wheels’ of capital flows.