134 P A R T I I Financial Markets
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where lnt the liquidity (term) premium for the n-period bond at time t, which is always positive and rises with the term to maturity of the bond, n.
Closely related to the liquidity premium theory is the preferred habitat theory, which takes a somewhat less direct approach to modifying the expectations hypothesis but comes up with a similar conclusion. It assumes that investors have a preference for bonds of one maturity over another, a particular bond maturity (preferred habitat) in which they prefer to invest. Because they prefer bonds of one maturity over another they will be willing to buy bonds that do not have the preferred maturity only if they earn a somewhat higher expected return. Because investors are likely to prefer the habitat of short-term bonds over that of longer-term bonds, they are willing to hold long-term bonds only if they have higher expected returns. This reasoning leads to the same Equation 3 implied by the liquidity premium theory with a term premium that typically rises with maturity.
The relationship between the expectations theory and the liquidity premiums and preferred habitat theories is shown in Figure 5. There we see that because the liquidity premium is always positive and typically grows as the term to maturity increases, the yield curve implied by the liquidity premium theory is always above the yield curve implied by the expectations theory and generally has a steeper slope.
A simple numerical example similar to the one we used for the expectations hypothesis further clarifies what the liquidity premium and preferred habitat theories in Equation 3 are saying. Again suppose that the one-year interest rate over the next five years is expected to be 5, 6, 7, 8, and 9%, while investorsÕ preferences for holding short-term bonds means that the liquidity premiums for oneto five-year bonds are 0, 0.25, 0.5, 0.75, and 1.0%, respectively. Equation 3 then indicates that the interest rate on the two-year bond would be:
5% 6% 0.25% 5.75%
2
F I G U R E 5 The Relationship
Between the Liquidity Premium
(Preferred Habitat) and Expectations
Theory
Because the liquidity premium is always positive and grows as the term to maturity increases, the yield curve implied by the liquidity premium and preferred habitat theories is always above the yield curve implied by the expectations theory and has a steeper slope. Note that the yield curve implied by the expectations theory is drawn under the scenario of unchanging future one-year interest rates.
Interest |
Liquidity Premium (Preferred Habitat) Theory |
Rate, int |
Yield Curve |
Liquidity
Premium, lnt
Expectations Theory
Yield Curve
Years to Maturity, n
C H A P T E R 6 The Risk and Term Structure of Interest Rates |
135 |
while for the five-year bond it would be:
5% 6% 7% 8% 9% 1% 8% 5
Doing a similar calculation for the one-, three-, and four-year interest rates, you should be able to verify that the oneto five-year interest rates are 5.0, 5.75, 6.5, 7.25, and 8.0%, respectively. Comparing these findings with those for the expectations theory, we see that the liquidity premium and preferred habitat theories produce yield curves that slope more steeply upward because of investorsÕ preferences for shortterm bonds.
LetÕs see if the liquidity premium and preferred habitat theories are consistent with all three empirical facts we have discussed. They explain fact 1 that interest rates on different-maturity bonds move together over time: A rise in short-term interest rates indicates that short-term interest rates will, on average, be higher in the future, and the first term in Equation 3 then implies that long-term interest rates will rise along with them.
They also explain why yield curves tend to have an especially steep upward slope when short-term interest rates are low and to be inverted when short-term rates are high (fact 2). Because investors generally expect short-term interest rates to rise to some normal level when they are low, the average of future expected shortterm rates will be high relative to the current short-term rate. With the additional boost of a positive liquidity premium, long-term interest rates will be substantially above current short-term rates, and the yield curve would then have a steep upward slope. Conversely, if short-term rates are high, people usually expect them to come back down. Long-term rates would then drop below short-term rates because the average of expected future short-term rates would be so far below current shortterm rates that despite positive liquidity premiums, the yield curve would slope downward.
The liquidity premium and preferred habitat theories explain fact 3 that yield curves typically slope upward by recognizing that the liquidity premium rises with a bondÕs maturity because of investorsÕ preferences for short-term bonds. Even if shortterm interest rates are expected to stay the same on average in the future, long-term interest rates will be above short-term interest rates, and yield curves will typically slope upward.
How can the liquidity premium and preferred habitat theories explain the occasional appearance of inverted yield curves if the liquidity premium is positive? It must be that at times short-term interest rates are expected to fall so much in the future that the average of the expected short-term rates is well below the current short-term rate. Even when the positive liquidity premium is added to this average, the resulting longterm rate will still be below the current short-term interest rate.
As our discussion indicates, a particularly attractive feature of the liquidity premium and preferred habitat theories is that they tell you what the market is predicting about future short-term interest rates just from the slope of the yield curve. A steeply rising yield curve, as in panel (a) of Figure 6, indicates that short-term interest rates are expected to rise in the future. A moderately steep yield curve, as in panel (b), indicates that short-term interest rates are not expected to rise or fall much in the future. A flat yield curve, as in panel (c), indicates that short-term rates are expected to fall moderately in the future. Finally, an inverted yield curve, as in panel (d), indicates that short-term interest rates are expected to fall sharply in the future.
136 P A R T I I Financial Markets
Yield to |
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Maturity |
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(a ) Future short-term interest rates expected to rise
(b)Future short-term interest rates expected to stay the same
Yield to |
Yield to |
Maturity |
Maturity |
Term to Maturity
(c)Future short-term interest rates expected to fall moderately
Term to Maturity
(d)Future short-term interest rates expected to fall sharply
F I G U R E 6 Yield Curves and the Market’s Expectations of Future Short-Term Interest Rates According to the Liquidity Premium Theory
Evidence on the Term Structure
In the 1980s, researchers examining the term structure of interest rates questioned whether the slope of the yield curve provides information about movements of future short-term interest rates.6 They found that the spread between longand short-term interest rates does not always help predict future short-term interest rates, a finding that may stem from substantial fluctuations in the liquidity (term) premium for longterm bonds. More recent research using more discriminating tests now favors a different view. It shows that the term structure contains quite a bit of information for the very short run (over the next several months) and the long run (over several years)
6Robert J. Shiller, John Y. Campbell, and Kermit L. Schoenholtz, ÒForward Rates and Future Policy: Interpreting the Term Structure of Interest Rates,Ó Brookings Papers on Economic Activity 1 (1983): 173Ð217; N. Gregory Mankiw and Lawrence H. Summers, ÒDo Long-Term Interest Rates Overreact to Short-Term Interest Rates?Ó
Brookings Papers on Economic Activity 1 (1984): 223Ð242.
138 |
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January 15, 1981 |
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March 28, 1985 |
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May 16, 1980 |
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March 3, 1997 |
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January 23, 2003 |
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F I G U R E 7 |
Yield Curves for U.S. Government Bonds |
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Sources: Federal Reserve Bank of St. Louis; U.S. Financial Data, various issues; Wall Street Journal, various dates.
The steep upward-sloping yield curves on March 28, 1985, and January 23, 2003, indicated that short-term interest rates would climb in the future. The long-term interest rate is above the short-term interest rate when shortterm interest rates are expected to rise because their average plus the liquidity premium will be above the current short-term rate. The moderately upward-sloping yield curves on May 16, 1980, and March 3, 1997, indicated that short-term interest rates were expected neither to rise nor to fall in the near future. In this case, their average remains the same as the current shortterm rate, and the positive liquidity premium for longer-term bonds explains the moderate upward slope of the yield curve.
Summary
1.Bonds with the same maturity will have different interest rates because of three factors: default risk, liquidity, and tax considerations. The greater a bondÕs default risk, the higher its interest rate relative to other bonds; the greater a bondÕs liquidity, the lower its
interest rate; and bonds with tax-exempt status will have lower interest rates than they otherwise would. The relationship among interest rates on bonds with the same maturity that arise because of these three factors is known as the risk structure of interest rates.
C h a p t e r |
The Stock Market, the |
Theory of |
7 |
Rational Expectations, |
and the |
Efficient Market Hypothesis
Rarely does a day go by that the stock market isnÕt a major news item. We have witnessed huge swings in the stock market in recent years. The 1990s were an extraordinary decade for stocks: the Dow Jones and S&P 500 indexes increased more than 400%, while the tech-laden NASDAQ index rose more than 1,000%. By early 2000, both indexes had reached record highs. Unfortunately, the good times did not last, and many investors lost their shirts. Starting in early 2000, the stock market began to decline: the NASDAQ crashed, falling by over 50%, while the Dow Jones and S&P 500 indexes fell by 30% through January 2003.
Because so many people invest in the stock market and the price of stocks affects the ability of people to retire comfortably, the market for stocks is undoubtedly the financial market that receives the most attention and scrutiny. In this chapter, we look at how this important market works.
We begin by discussing the fundamental theories that underlie the valuation of stocks. These theories are critical to understanding the forces that cause the value of stocks to rise and fall minute by minute and day by day. Once we have learned the methods for stock valuation, we need to explore how expectations about the market affect its behavior. We do so by examining the theory of rational expectations. When this theory is applied to financial markets, the outcome is the efficient market hypothesis. The theory of rational expectations is also central to debates about the conduct of monetary policy, to be discussed in Chapter 28.
Theoretically, the theory of rational expectations should be a powerful tool for analyzing behavior. But to establish that it is in reality a useful tool, we must compare the outcomes predicted by the theory with empirical evidence. Although the evidence is mixed and controversial, it indicates that for many purposes, the theory of rational expectations is a good starting point for analyzing expectations.
Computing the Price of Common Stock
Common stock is the principal way that corporations raise equity capital. Holders of common stock own an interest in the corporation consistent with the percentage of outstanding shares owned. This ownership interest gives stockholdersÑthose who hold stock in a corporationÑa bundle of rights. The most important are the right to vote and to be the residual claimant of all funds flowing into the firm (known as cash flows), meaning that the stockholder receives whatever remains after all other
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claims against the firmÕs assets have been satisfied. Stockholders are paid dividends from the net earnings of the corporation. Dividends are payments made periodically, usually every quarter, to stockholders. The board of directors of the firm sets the level of the dividend, usually upon the recommendation of management. In addition, the stockholder has the right to sell the stock.
One basic principle of finance is that the value of any investment is found by computing the value today of all cash flows the investment will generate over its life. For example, a commercial building will sell for a price that reflects the net cash flows (rents Ð expenses) it is projected to have over its useful life. Similarly, we value common stock as the value in todayÕs dollars of all future cash flows. The cash flows a stockholder might earn from stock are dividends, the sales price, or both.
To develop the theory of stock valuation, we begin with the simplest possible scenario: You buy the stock, hold it for one period to get a dividend, then sell the stock. We call this the one-period valuation model.
The One-Period
Valuation Model
Suppose that you have some extra money to invest for one year. After a year, you will need to sell your investment to pay tuition. After watching CNBC or Wall Street Week on TV, you decide that you want to buy Intel Corp. stock. You call your broker and find that Intel is currently selling for $50 per share and pays $0.16 per year in dividends. The analyst on Wall Street Week predicts that the stock will be selling for $60 in one year. Should you buy this stock?
To answer this question, you need to determine whether the current price accurately reflects the analystÕs forecast. To value the stock today, you need to find the present discounted value of the expected cash flows (future payments) using the formula in Equation 1 of Chapter 4. Note that in this equation, the discount factor used to discount the cash flows is the required return on investments in equity rather than the interest rate. The cash flows consist of one dividend payment plus a final sales price. When these cash flows are discounted back to the present, the following equation computes the current price of the stock:
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Div1 |
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ke ) |
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=the current price of the stock. The zero subscript refers to |
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=the dividend paid at the end of year 1. |
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price of the stock. |
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To see how Equation 1 works, letÕs compute the price of the Intel stock if, after careful consideration, you decide that you would be satisfied to earn a 12% return on the investment. If you have decided that ke = 0.12, are told that Intel pays $0.16 per year in dividends (Div1 = 0.16), and forecast the share price of $60 for next year (P1 = $60), you get the following from Equation 1:
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$0.14 $53.57 $53.71 |
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C H A P T E R 7 The Stock Market, the Theory of Rational Expectations, and the Efficient Market Hypothesis 143
The Generalized
Dividend
Valuation Model
Based on your analysis, you find that the present value of all cash flows from the stock is $53.71. Because the stock is currently priced at $50 per share, you would choose to buy it. However, you should be aware that the stock may be selling for less than $53.71, because other investors place a different risk on the cash flows or estimate the cash flows to be less than you do.
Using the same concept, the one-period dividend valuation model can be extended to any number of periods: The value of stock is the present value of all future cash flows. The only cash flows that an investor will receive are dividends and a final sales price when the stock is ultimately sold in period n. The generalized multi-period formula for stock valuation can be written as:
P0 |
D1 |
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... |
Dn |
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(2) |
(1 ke )1 |
(1 ke )2 |
(1 ke )n |
(1 ke )n |
If you tried to use Equation 2 to find the value of a share of stock, you would soon realize that you must first estimate the value the stock will have at some point in the future before you can estimate its value today. In other words, you must find Pn in order to find P0. However, if Pn is far in the future, it will not affect P0. For example, the present value of a share of stock that sells for $50 seventy-five years from now using a 12% discount rate is just one cent [$50/(1.1275)=$0.01]. This reasoning implies that the current value of a share of stock can be calculated as simply the present value of the future dividend stream. The generalized dividend model is rewritten in Equation 3 without the final sales price:
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Consider the implications of Equation 3 for a moment. The generalized dividend model says that the price of stock is determined only by the present value of the dividends and that nothing else matters. Many stocks do not pay dividends, so how is it that these stocks have value? Buyers of the stock expect that the firm will pay dividends someday. Most of the time a firm institutes dividends as soon as it has completed the rapid growth phase of its life cycle.
The generalized dividend valuation model requires that we compute the present value of an infinite stream of dividends, a process that could be difficult, to say the least. Therefore, simplified models have been developed to make the calculations easier. One such model is the Gordon growth model, which assumes constant dividend growth.
Many firms strive to increase their dividends at a constant rate each year. Equation 4 rewrites Equation 3 to reflect this constant growth in dividends:
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(1 k |
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where |
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=the expected constant growth rate in dividends |
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