IS-LM Model

Is lm

http://www.slideshare.net/ProfMKGhadoliya/is-lm-28666799

1. 1. The IS-LM Model A General Framework for Macroeconomic Analysis Prof. M.K.Ghadoliya Director, JNU Jaipur
2. 2. Chapter 9. Introduction  In this lecture we integrate the elements of our model that you have covered separately It develops a graphical depiction of our theory that is called the IS-LM model. – IS and LM refer to two equilibrium conditions in the model (investment equals saving; money demand, or liquidity preference, equals money supply).
3. 3. The FE Line   I will be using some diagrams that plot the real rate of interest, r, and output Y on the axes. Recall that labor market equilibrium determines a quantity of labor, which, via the production function, determines a full-employment level of output. – Since that level of output presumably does not depend on the rate of interest, we can plot the full-employment line as a vertical line in a diagram in which r and Y appear on vertical and horizontal axes.
4. 4. Figure 9.1 The FE line
5. 5. FE Curve Shifters Variable Increases FE Curve Shifts Productivity Right Labor Supply (Population) Right Capital Stock Right
6. 6. Deriving the IS Curve  Recall the Goods Market Equilibrium Condition: d d S =I
7. 7. Consider a Rise in Income  As income rises, the desired saving curve shifts right, and the equilibrium rate of interest falls as we slide down the desired investment curve (next slide).
8. 8. Goods Market Equilibrium S r r0 I Sd = Id Sd , I d
9. 9. Goods Market Equilibrium S r S (Higher Income) r0 r1 I Sd = Id Sd , I d
10. 10. Deriving IS   The previous slide shows that as income varies and goods market equilibrium is maintained, a higher value of income is associated with a lower value of the expected real interest rate Plot the income-interest rate pairs that satisfy the goods market equilibrium condition to get the IS curve – The inverse relationship between income and interest rate implies that the IS curve is downward sloping
11. 11. Figure 9.2 Deriving the IS curve
12. 12. Shifting IS   Recall that IS was derived by considering how the desired saving curve moved along the desired investment curve as income changed. Suppose a shock (say a government spending increase) causes saving to decline at each level of income – –  Then the interest rate is higher at each level of income. Then we must redraw IS, with higher r for each level of Y. IS has shifted to the right. For other shocks that shift saving or investment schedules, we can also infer how IS shifts.
13. 13. IS Curve Shifters Variable Increases IS Curve Shifts Expected Future Output Right Wealth Right Government Spending Right Taxes None (Ricardian) or Left Expected future MPK Right Effective Tax Rate on K Left
14. 14. The LM Curve  The IS plots income interest-rate pairs such that desired spending is equal to output, or desired saving is equal to desired investment  We will now derive the LM curve, which plots income-interest rate pairs such that the quantity of money demanded is equal to the quantity of money supplied.
15. 15. Money Market Equilibrium Revisited
16. 16. The LM Curve
17. 17. The Derivation of LM
18. 18. LM Curve Shifters Variable Increases LM Curve Shifts Nominal Money Supply Right Price Level Left Expected Inflation Right Nominal interest rate on money im Left Anything Else Increasing the Demand for Money Left
19. 19. General Equilibrium in the IS-LM Model  In general equilibrium, all markets satisfy their respective equilibrium conditions. –  Labor, Goods, and Money Markets Must all be in equilibrium. The logic of general equilibrium: – – – The labor market determines output. Given output (income) the goods market then determines an interest rate. Given output, the interest rate, and the expected inflation rate, then the money market determines the price level.
20. 20. General Equilibrium in the IS-LM Model (Diagram)
21. 21. Equilibrium: A Coincidence?      Labor Market equilibrium requires that the economy be on the FE line Goods Market equilibrium requires that the economy be on the IS Curve Money Market equilibrium requires that the economy be on the LM Curve General equilibrium requires that the economy be on all three curves simultaneously Does this require a happy coincidence? (No)
22. 22. Review on Equilibrium  To review, output is determined by the FE line  Given output the intersection of IS and FE determines the interest rate  Finally, the price level adjusts so that LM intersects both IS and FE
23. 23. Timing of Movement to Equilibrium   Our model, as formulated, does not tell us the order in which variables move—we just infer that the economy moves from one equilibrium to another (after a shock). Here are some thoughts on timing: – – – – Interest rates (and financial markets generally) adjust very quickly Nominal (and real) wages adjust slowly (often wages are set for long periods of time Prices may also adjust slowly The goods market adjusts with intermediate speed (we often see unanticipated inventory movements, but firms may alter production before revising prices)
24. 24. A Look Ahead: Keynesian and Classical Views  We will say much more about “Keynesian” and “Classical” macroeconomic theories  Keynesians emphasize the short-term rigidity of prices and wages  Classical economists emphasize that all markets reach equilibria rather quickly
25. 25. The End