<P> In economics, the consumption function describes a relationship between consumption and disposable income . The concept is believed to have been introduced into macroeconomics by John Maynard Keynes in 1936, who used it to develop the notion of a government spending multiplier . </P> <P> Its simplest form is the linear consumption function used frequently in simple Keynesian models: </P>

The intercept term of the linear investment function​ measures