Keynesian economics (also called Keynesian theory) are the group of macroeconomic schools of thought based on the ideas of 20th-century economist John Maynard Keynes. Keynesian economists believe that aggregate demand (total spending in the economy) does not necessarily equal aggregate supply (the total productive capacity of the economy). Instead it is influenced by a host of factors and sometimes behaves erratically, affecting production, employment and inflation.
What is Neoclassical Economics? : Debating the Origins, Meaning and Significance (Hardcover)