Gordon Tullock has argued Hayek's analysis incorrectly predicted governments in much of Europe in the late 20th century would descend into totalitarianism. He uses Sweden, in which the government at that time controlled 63 percent of GNP, as an example to support his argument that the basic problem with "The Road to Serfdom" is "that it offered predictions which turned out to be false. The steady advance of government in places such as Sweden has not led to any loss of non-economic freedoms." While criticizing Hayek, Tullock still praises the classical liberal notion of economic freedom, saying, "Arguments for political freedom are strong, as are the arguments for economic freedom. We needn’t make one set of arguments depend on the other." However, according to Robert Skidelsky, Hayek "safeguarded himself from such retrospective refutation". Skidelsky argues that Hayek's argument was contingent, and that, "By the 1970s there was some evidence of the slippery slope ... and then there was Thatcher. Hayek's warning played a critical part in her determination to 'roll back the state.'"