The credit cycle is the expansion and contraction of access to credit over time. Some economists, including Barry Eichengreen, Hyman Minsky, and other Post-Keynesian economists, and some members of the Austrian school, regard credit cycles as the fundamental process driving the business cycle. However, mainstream economists believe that the credit cycle cannot fully explain the phenomenon of business cycles, with long term changes in national savings rates, and fiscal and monetary policy, and related multipliers also being important factors.