The beauty of this relationship for policy makers is that they decide which level of unemployment they want and then set the inflation rate to achieve it. This evidence completed the Keynesian revolution. The paradigm had a theoretical framework and empirical evidence. Most governments adopted Keynesian style demand management policies. They seemed to work well at first but as time progressed it was taking successively higher and higher levels of inflation to reduce unemployment. This led some to question Keynes’ argument. The model was mostly abandoned in the 1970s when the phenomenon of stagflation was observed. This is when an economy experiences rising inflation and unemployment at the same time. Keynes’ model was unable to explain this and so had clearly missed something important.Milton Friedman was perhaps the most important figure in the so-called monetarist counter revolution which followed the breakdown of Keynes’ model. Friedman stated that attempts by the government to stimulate aggregate demand would destabilise the economy. He described the concept of the natural rate of unemployment. This is the unemployment which exists in equilibrium. Friedman claimed that this unemployment was not the result of insufficient demand. He stated that this sort of unemployment was created by supply side factors. Some workers, for example, may have obsolete skills. The government should introduce education and training programmes so that the workers can find work on their own if it wishes to reduce unemployment. Also included in the natural rate of unemployment was cyclical and frictional unemployment i.e. workers who are unemployed because of the time of year and workers who are between jobs. Trying to reduce this unemployment by increasing demand in the economy would only create inflation. This removed the rationale for government intervention.