INVESTMENT LINE: A graphical depiction of the relation between business investment expenditures and national income that forms one of the key building blocks for Keynesian economics. The slope of this line is positive, greater than zero, less than one, and goes by the name marginal propensity to invest. The vertical intercept of the investment line is autonomous investment. The aggregate expenditures line used in the Keynesian cross is obtained by adding this investment line, as well as, government purchases and net exports, to the consumption line. The investment line is also combined with the saving line in saving-investment model used in Keynesian economics. See also | Keynesian economics | investment expenditures | national income | marginal propensity to invest | aggregate expenditures | aggregate expenditures line | Keynesian cross | saving-investment model | induced investment | autonomous investment |
