Original sentence: A fundamental concept in such Keynesian analysis is the relationship between inflation and unemployment, called the Phillips curve.Another cause of inflation occurs when there are many people and organisations with enough market power to increase their prices.For example, Monetarist economists believe that the link is very strong; Keynesian economics by contrast typically emphasise the role of aggregate demand in the economy rather than the money supply in determining inflation.Inflation is the rise in the general level of prices.Inflation may be caused by an increase in the quantity of money in circulation.The money supply is also thought to play a role in determining levels of more moderate levels of inflation, although there are differences of opinion on how important it is.This is equivalent to a fall in the value or  purchasing power of money
Edited sentence: A fundamental concept in Keynesian analysis is the relationship between inflation and unemployment, called the Phillips curve.According to the Merriam-Wrbster dictionary, "Inflation is an increase in the volume of money and credit relative to available goods and services resulting in a continuing rise in the general price level".Inflation is, by the above definition, the result of an increase in the quantity of money in circulation.Keynsians respond to this criticism by stating that Keynsian theory still holds because the period of stagflation was never identified as a recession.This suggested to many that Keynsian economic theory simply does not reflect the true behaviour of the market