After the military took over the government in 1973, a period of dramatic economic changes began. The military junta appointed a group of Chilean economists who had been educated in the United States at the University of Chicago. The Chicago Boys advocated "laissez-faire", free-market, neoliberal, and fiscally conservative policies, in stark contrast to the extensive nationalization and centrally-planned economic programs supported by Allende, and the import substitution industrialization and structuralist economics supported by Chilean governments since the Great Depression. In a shock therapy, Chile was drastically transformed from an economy with a protected market, with strong government intervention, into a liberalized, world-integrated economy, where market forces were left free to guide most of the economy's decisions. Before 1973 the role of the state was to promote investment and industrialization. The Chicago Boys restricted government intervention and public enterprise activities. Businesses and lands expropriated during the presidency of Allende were re-privatized (with the exception of the copper mines). Price controls were abolished, import liberalized, the financial market and capital flows were deregulated. Labor unions were suppressed. Direct taxes and progressive taxes were reduced or abolished while indirect taxes were raised. The central bank raised interest rates from 49.9% to 178%. Thereby inflation could be lowered at the expected price of a sharp recession. When unemployment doubled some public work programmes were installed.