多恩布什 宏观经济学 第十版 英文课件Chapter_10

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Downward sloping IS curve
10-13
The Interest Rate and AD: The IS Curve
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We can also derive the IS curve using the goods market equilibrium condition:
Y = AD = A + c(1 − t )Y − bi ⇒ Y − c(1 − t )Y = A − bi Y (1 − c(1 − t )) = A − bi Y = αG ( A − bi )
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This chapter:
introduces money and monetary policy builds an explicit framework of analysis within which to study the interaction of goods markets and assets market

What determines interest rates? What is the role of interest rates in the business cycle?

10-3
Introduction
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Figure 10-1 shows the interest rate on Treasury bills = the payment received by someone who lends to the U.S. government
Introduction
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Money plays a central role in the determination of income and employment
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Interest rates are a significant determinant of aggregate spending → Fed controls the money supply in the United States The stock of money, interest rates, and the Fed were noticeably absent from the model developed in the last chapter

A change in i will change the equilibrium
10-10
The Interest Rate and AD: The IS Curve
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AD = A + c(1 − t )Y − bi (2) Derive the IS curve using figure 10-5
10-4
Introduction
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Figure 10-2 shows the strong link between money and output growth
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[Insert Figure 10-2 here]
This chapter explores the link from money to interest rates to output
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[Insert Figure 10-1 here]
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Ex. At an interest rate of 5%, a $100 loan to the government will earn $5 in interest Figure 10-1 shows that interest rates: Are high just before a recession Drop during the recession Rise during the recovery
10-9
The Interest Rate and AD: The IS Curve
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Need to modify the AD function of the last chapter to reflect the new planned investment spending schedule
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Derived in two steps:
1. 2.
Link between interest rates and investment Link between investment demand and AD
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Investment is no longer treated as exogenous, but dependent upon interest rates ( Interest Rate and AD: The IS Curve
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AD = A + c(1 − t )Y − bi (2) Derive the IS curve using figure 10-5

[Insert Figure 10-5 here again]
Consider a lower interest rate, i2 Shifts the AD curve upward to AD’ with an intercept of A − bi2 Given the increase in AD, the equilibrium shifts to point E2, with an associated income level of Y2 Plot the pair (i2, Y2) in panel (b) for another point on the IS curve
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IS-LM model is the core of short-run macroeconomics
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Maintains the details of earlier model, but adds the interest rate as an additional determinant of aggregate demand Includes the goods market and the money market, and their link through interest rates and income

[Insert Figure 10-5 here]

For a given interest rate, i1, the last term in equation (2) is constant → can draw the AD function with an intercept of A − bi1 The equilibrium level of income is Y1 at point E1 Plot the pair (i1, Y1) in the bottom panel as point E1 → a point on the IS curve Combination of i and Y that clears the goods market
10-1
Chapter 10
Money, Interest, and Income
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McGraw-Hill/Irwin Macroeconomics, 10e
© 2008 The McGraw-Hill Companies, Inc., All Rights Reserved. 10-2
Investment and the Interest Rate
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I = I − bi (1) The position of the I schedule is determined by:
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[Insert Figure 10-4 here]
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The slope, b If investment is highly responsive to i, the investment schedule is almost flat If investment responds little to i, the investment schedule is close to vertical Level of autonomous spending An increase in I shifts the investment schedule out A decrease in I shifts the investment schedule in
Investment demand is lower the higher are interest rates
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Interest rates are the cost of borrowing money Increased interest rates raise the price to firms of borrowing for capital equipment → reduce the quantity of investment demand
All points on the IS curve represent combinations of i and income at which the goods market clears → goods market equilibrium schedule
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Figure 10-5 shows the negative relationship between i and Y


10-12
The Interest Rate and AD: The IS Curve
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We can apply the same procedure to all levels of i to generate additional points on the IS curve