In economics, the Pigou effect is the stimulation of output and employment caused by increasing consumption due to a rise in real balances of wealth, particularly during deflation. The term was named after Arthur Cecil Pigou by Don Patinkin in 1948. Real wealth was defined by Arthur Cecil Pigou as the summation of the money supply and government bonds divided by the price level. He argued that Keynes' General Theory was deficient in not specifying a link from "real balances" to current consumption and that the inclusion of such a "wealth effect" would make the economy more "self correcting" to drops in aggregate demand than Keynes predicted. Because the effect derives from changes to the "Real Balance", this critique of Keynesianism is also called the Real Balance effect. History The Pigou effect was first popularised by Arthur Cecil Pigou in 1943, in The Classical Stationary State an article in the Economic Journal. He had proposed the link from balances to consumption earlier, and Gottfried Haberler had made a similar objection the year after the General Theorys publication. Following the tradition of classical economics, Pigou favoured the idea of "natural rates" to which the economy would return in most cases, although he acknowledged that sticky prices might still prevent reversion to natural output levels after a demand shock. Pigou saw the "Real Balance" effect as a mechanism to fuse Keynesian and classical models. Integration with Keynesian aggregate demand Keynes argued with that a drop in aggregate demand could lower both employment and the price level in unison, an occurrence observed in the deflationary depression. In the IS-LM framework of Keynesian economics as formalised by John Hicks, a negative aggregate demand shock would shift the IS curve left; as a result, a simultaneously falling wage and price level would shift the LM curve downward due to a rising real money supply - this is referred to as the Keynes effect. The Pigou effect would in turn counter the fall in aggregate demand, through rising current real balances raising expenditures via the Income effect, thus shifting the IS curve back towards the right. Pigou's hypothesis and the liquidity trap An economy in a liquidity trap cannot use monetary stimulus to increase output because there is little connection between personal income and money demand. John Hicks thought that this might be another reason (along with sticky prices) for persistently high unemployment. However, the Pigou