Within weeks of taking office, Britain’s new prime minister, Liz Truss, and her chancellor of the exchequer, Kwasi Kwarteng, proposed a radical new set of economic measures that echoed the trickle-down policies of Margaret Thatcher and Ronald Reagan – heavy on tax cuts for the rich and deregulation.Last Monday, after a backlash from investors, economists and members of his own party, Mr Kwarteng reversed one of the proposals, deciding against abolishing the tax rate of 45% on the highest earners. But proposals for other tax cuts worth tens of billions...