The economic history of the last 30 years is the triumph of monetarism over neo-Keynesian economics. When conventional Keynesian measures proved incapable of taming the inflation and high unemployment of the 1970s, new Federal Reserve Chairman Paul Volcker made what his successor later described as one of the most important policy changes in the last 50 years. He raised interest rates to previously unthinkable levels in a successful attempt to reduce the money supply, which broke the inflationary cycle, and, after a brief recession, led to a great economic expansion that lasted for nearly 20 years.