The IS Curve

The IS curve, also known as the investment-savings curve, is a graphical representation of the relationship between interest rates and real GDP in the economy. It shows the equilibrium level of real GDP that is consistent with a given level of interest rates.

The IS curve is derived from the Keynesian theory of macroeconomics, which suggests that investment and savings are the two key determinants of aggregate demand. The curve is downward sloping, indicating that as interest rates increase, investment decreases, and savings increase. This leads to a decrease in aggregate demand and a lower level of real GDP.

The IS curve is often used in conjunction with the LM curve, which represents the relationship between interest rates and the demand for money. Together, these two curves form the basis of the IS-LM model, which is widely used in macroeconomic analysis and policy-making.

The IS curve can be shifted by changes in factors such as government spending, taxes, or exports. For example, an increase in government spending will shift the IS curve to the right, indicating a higher equilibrium level of real GDP at any given interest rate. Similarly, an increase in exports will shift the IS curve to the right, as it increases aggregate demand and GDP.