An interview with the Hudson Insitute's Dr Irwin Stelzer, an influential advocate of free market economics and adviser to Rupert Murdoch. For years the economies of the US and Britain have had a Teflon quality, but confidence has evaporated. The US housing and mortgage markets are in trouble. The British government has had to intervene in the Northern Rock crisis. Has the bubble burst? Stephen Sackur asks Dr Stelzer: what's gone wrong and who's to blame?