Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
Chapter 6
Bonds, Bond Prices, and the Determination of Interest
Rates
Chapter Overview
If we want to understand the financial system, particularly the bond market, we must
understand the relationship between bond prices and interest rates, the determination of
bond prices in the market (by supply and demand), and also why bonds are risky. These
issues will be covered in this chapter.
Learning Objectives: Establish an understanding of:
Present value and bond pricing
Relationship of prices, yields, and returns
Key drivers of bond prices
Risks of default, inflation risk, and interest-rate changes
Important Points of the Chapter
Any financial arrangement involving the current transfer of resources from a lender to a
borrower, with a transfer back at some time in the future, is a form of a bond. The ease
with which individuals, corporations, and governments borrow is essential to the
functioning of our economic system. While the depth and complexity of bond markets
has increased in modern times, many of their original features (dating back to the 16th and
17th centuries) remain.
Application of Core Principles
Principle #1: Time. The price of a Treasury bill is the present value of the future
payments it will make. The shorter the time period until the payments are made, the
higher the price of the bond.
Principle #4: Markets. Equilibrium in the bond market occurs when supply and demand
are equal. At a higher price there would be an excess supply of bonds, which would push
the price down. At a lower price there would be an excess demand for bonds, which
would push the price up. Only when supply and demand are equal can there be
equilibrium.
Principle #2: Risk. Risk arises from the fact that an investment has many possible payoffs
during the time horizon for which it is held. Certain risks affect the premium that
investors require over the risk-free return. Risk requires compensation.
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Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
Teaching Tips/Student Stumbling Blocks
This chapter continues the use of present value analysis to analyze how bond
prices are determined. You may wish to begin with a review of the tools from
Chapter 5.
Spend time going carefully through the examples from the text and reinforce
concepts by assigning end-of-chapter problems.
Features in this Chapter
Your Financial World: Know Your Mortgage
A large number of people with adjustable rate mortgages (ARMs) underestimate how
much the interest rate can change. Important things to know are what interest-rate index
the mortgage rate is based; how big is the mortgage rate margin above the interest-rate
index on which it is based; how frequently the rate is adjusted; does it have an initial
discount rate that will rise, and by how much; whether there is a cap on how much the
rate can rise both at one adjustment and over the life of the loan; whether there is a
payment cap, and, if the payment cap is reached, will the principal amount of the loan
then increase (this is negative amortization); and finally, whether it can be converted to a
fixed-rate mortgage.
Tools of the Trade: Reading the Bond Page
This section illustrates and explains how to read a bond table. The U.S. Treasury alone
had nearly 300 coupon-bearing instruments outstanding. The table shows that the yields
on government bonds vary significantly over time and substantially across countries.
Your Financial World: Understanding the Ads in the Newspaper
Suppose you see an ad for an investment company stating that their bond mutual funds
returned 13.5% over the last year. How is this possible if interest rates have been pretty
low? The answer is that the ad is about last year’s holding period return, when interest
rates were falling. The resulting rise in bond prices (due to the falling rates) meant the
return was more than just the interest paid by the bonds; it also included capital gains. In
a rising interest rate environment the holding period return will be negatively affected by
decreases in bond prices. That’s one reason why past performance is indeed not an
indicator of future returns.
Applying the Concept: When Russia Defaulted
On numerous occasions, investors’ concerns about increased risk in certain areas of the
globe have led to a significant shift in the demand for U.S. Treasury bonds. The default
by the Russian government in the fall of 1998 was such an occasion. As a result of the
default no one wanted to hold Russian debt or, for that matter, the debt of any emerging
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Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
market country, and so the demand for safe U.S. Treasury bonds increased. The prices of
U.S. Treasuries rose and their yields fell as their perceived riskiness declined.
Applying the Concept: Securitization
Securitization is the process by which financial institutions pool various assets that
generate a stream of payments and transform them into a bond that gives the bondholder
a claim on those payments. Mortgage-backed securities are just one form of
securitization. Any stream of payments can be used to create a bond. Securitization uses
the effiency of markets to lower the cost of borrowing by facilitating diversification of
risk, making assets liquid, allowing greater specialization in the business of finance,
broadening markets, and fostering innovation.
Your Financial World: Bonds Indexed to Inflation
There is a type of U.S. Treasury bond that compensates investors for inflation. The bond
promises to pay a fixed interest rate plus the change in the consumer price index. The
U.S. Treasury sells two types of such bonds, Series I savings bonds and Treasury
Inflation Protection Securities (or TIPS). The difference between the two is the amount
that can be purchased (savings bonds can be bought for as little as $50, while TIPS
require a $1000 investment).
In the News: Gross’s Burning Bond Market Fails to Frighten Investors
Investors who lost a significant amount of retirement savings in the financial crisis
shifted to bonds to reduce risk. While investors who hold bonds until they mature don’t
lose money unless the issuer defaults, those who trade can suffer losses if the interest
rates rise. Further, long-term Treasuries had as many losing years as stocks did n the last
85 years.
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Lessons of the Article: Some investors view longterm bonds as much safer
than stocks, but losses on such bonds are similarly frequent, and their
inflationadjusted returns are lower on average. With bond yields near record
lows in 2012 and the Federal Reserve pursuing an accommodative monetary
policy, worries about bonds encouraged some professional investors to favor
equities or to purchase TIPS despite their subzero inflationadjusted yields.
Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
Additional Teaching Tools
In an article from Business Week (“Bonds: Sorting Through the Confusion”, January 6,
2010), David Bogoslaw writes, “Getting your investment portfolio’s bond allocation right
will not be easy in 2010 amid conflicting views on inflation from investment strategists
and policymakers.” Many experts are watching inflation on the fear that the Fed will not
withdraw the massive amounts of money in the economy as it begins to heat up.
However, these experts are not convinced that January was the time to enter the TIPS
market, as the payoff was not yet worth moving.
Virtual Tools
Use the withholding calculator on the IRS website to adjust the amount taken from your
paycheck. It is located at www.irs.gov.
Visit the web site of the Treasury to see how Series I and TIPS can be purchased; it is
located at http://www.fiscal.treasury.gov/.
For More Discussion
Joan Robinson once stated that anyone who bought an infinite-maturity consol would
have “to think he knows exactly what the rates of interest will be every day from now to
Kingdom Come.” Relate this to the discussion of interest rate risk in this chapter.
(Source: Robinson, Joan, “The Rate of Interest,” Econometrica 19 (1951): 92-111; she
was objecting to the version of the Expectations Hypothesis that relates forward interest
rates to expectations of future short term interest rates. This will be covered in more
detail in Chapter 7.)
Chapter Outline
I. Bond Prices
There are four basic types of bonds: zero-coupon bonds, which promise a single
future payment (like a U.S. Treasury Bill); fixed payment loans (like conventional
mortgages); coupon bonds, which make periodic interest payments and repay the
principal at maturity (like U.S. Treasury Bonds and most corporate bonds); and
consols, which make periodic interest payments but never repay the principal that was
borrowed. In this section we will see how each of these is priced.
A. Zero-Coupon Bonds
1. These are pure discount bonds (also called discount bonds) since they sell at a
price below their face value.
2. The difference between the selling price and the face value represents the
interest on the bond.
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Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
3. The price of such a bond, like a Treasury bill (called “T-bill”), is the present
value of the future payment.
4. The most common maturity of a T-bill is 6 months; the Treasury does not
issue them with a maturity greater than 1 year.
5. The shorter the time until the payment is made the higher the price of the
bond, so 6 month T-bills have a higher price that a one-year T-bill.
6. The interest rate and the price for the T-bill move inversely. If we know the
face value and the price then we can solve for the interest rate.
B. Fixed Payment Loans
1. Conventional home mortgages and car loans are examples of fixed payment
loans; they promise a fixed number of equal payments at regular intervals.
2. These loans are amortized, meaning that the borrower pays off the principal
along with the interest over the life of the loan. Each payment includes both
interest and some portion of the principal.
3. The price of the loan is the present value of all the payments.
C. Coupon Bonds
1. The value of a coupon bond is the present value of the periodic interest
payments plus the present value of the principal repayment at maturity.
2. The latter part, the repayment of the principal, is just like a zero-coupon bond.
D. Consols
1. A consol offers only periodic interest payments; the borrower never repays the
principal.
2. There are no privately issued consols because only governments can credibly
promise to make payments forever.
3. The price of a consol is the present value of all the future interest payments,
which is a bit complicated because there are an infinite number of payments.
II. Bond Yields
A. Yield to Maturity
1. The most useful measure of the return on holding a bond is called the yield to
maturity. This is the yield bondholders receive if they hold the bond to its
maturity when the final principal payment is made.
2. The yield to maturity can be calculated from the present value formula.
3. If the yield to maturity equals the coupon rate, the price of the bond is the
same as its face value. If the yield is greater than the coupon rate, the price is
lower; if the yield is below the coupon rate, the price is greater.
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Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
4. If you buy a bond at a price less than its face value you will receive its interest
and a capital gain, which is the difference between the price and the face
value. As a result you have a higher return than the coupon rate.
5. When the price is above the face value, the bondholder incurs a capital loss
and the bond’s yield to maturity falls below its coupon rate.
B. Current Yield
1. Current yield is a commonly used, easy-to-compute measure of the proceeds
the bondholder receives for making a loan.
2. It is the yearly coupon payment divided by the price.
3. The current yield measures that part of the return from buying the bond that
arises solely from the coupon payments; it ignores the capital gain or loss that
arises when the bond’s price differs from its face value.
4. The current yield moves inversely to the price; if the price is above the face
value, the current yield falls below the coupon rate. When the price falls
below the face value, the current yield rises above the coupon rate. If the
price and the face value are equal the current yield and the coupon rate are
equal.
5. Since the yield to maturity takes account of capital gains (and losses), when
the bond price is less than its face value the yield to maturity is higher than the
current yield, and if the price is greater than face value, the yield to maturity is
lower than the current yield, which is lower than the coupon rate.
C. Holding Period Returns
1. The investor’s return from holding a bond need not be the coupon rate.
2. Most holders of long-term bonds plan to sell them well before they mature,
and because the price of the bond may change in the time since its purchase,
the return can differ from the yield to maturity.
3. The greater the price change the more important the capital gain or loss
becomes as part of the holding period return.
4. The longer the term of the bond, the greater the price movements and
associated risk can be.
III. The Bond Market and the Determination of Interest Rates
To find out how bond prices are determined and why they change we need to look
at the supply and demand in the bond market. Let’s discuss the quantity of bonds
outstanding (the stock of bonds) and consider bonds prices rather than interest rates.
The analysis will consider the one-year zero-coupon bond.
A. Bond Supply, Bond Demand, and Equilibrium in the Bond Market
1. The bond supply curve is the relationship between the price and quantity of
bonds people are willing to sell, all other things being equal.
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Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
2. The bond supply curve is upward sloping; the higher the price of a bond, the
larger the quantity supplied will be because investors will be tempted to sell
bond that they hold and companies will find it advantageous to issue new
bonds.
3. The bond demand curve is the relationship between the price and quantity of
bonds that investors demand, all other things being equal.
4. The bond demand curve slopes down; as the price falls, the reward for
holding the bond rises so there is a greater quantity demanded.
5. Equilibrium in the market is the price at which the quantity demanded
equals the quantity supplied of bonds.
6. If the price is too high (above equilibrium) the excess supply of bonds will
push the price back down. If the price is too low (below equilibrium) the
excess demand for bonds will push it up.
7. Over time the supply and demand curves can shift, leading to changes in the
equilibrium price.
B. Factors that Shift Bond Supply
1. We can identify the factors that shift the supply curve for bonds:
a. Changes in government borrowing: the more governments borrow the
greater the quantity of bonds supplied, shifting the curve to the right.
b. Changes in business conditions: business-cycle expansions mean more
investment opportunities, prompting firms to increase their borrowing
and increasing the quantity of bonds supplied. By the same logic, weak
economic growth can lead to rising bond prices and lower interest rates.
c. Changes in expected inflation: bond issuers care about the real cost of
borrowing, so if inflation is expected to increase then the real cost falls
and the desire to borrow rises, resulting in the bond supply curve shifting
to the right.
d. Changes in corporate taxation: changes in the tax code are infrequent,
but when they occur they affect the quantity of bonds supplied. Tax
incentives that make investment less costly increase the quantity of
bonds supplied.
C. Factors that Shift Bond Demand
1. Six factors shift the demand for bonds:
a. Wealth: increases in wealth shift the demand for bonds to the right as
wealthier people invest more.
b. Expected inflation: a fall in expected inflation will shift the demand for
bonds to the right.
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Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
c. The expected return on stocks and other assets: if the return on bonds
rises relative to the return on alternative investments, the demand for
bonds will shift to the right.
d. Expected interest rates: changes in expected interest rates affect bond
prices; if interest rates are expected to fall, then bond prices are expected
to rise, and the demand for bonds shifts to the right.
e. Risk relative to alternatives: if a bond is less risky then the demand will
shift to the right.
f. The liquidity of bonds relative to alternatives: the more liquid an asset
the higher its demand, shifting the demand curve to the right.
D. Understanding Changes in Equilibrium Bond Prices and Interest Rates
1. An increase in expected inflation shifts bond supply to the right and bond
demand to the left. The two effects reinforce each other, resulting in a lower
bond price and a higher interest rate.
2. A business-cycle downturn shifts the bond supply to the left and the bond
demand to the left. In this case the bond price can rise or fall, depending on
which shift is greater. But interest rates tend to fall in recessions, so bond
prices are likely to increase.
IV. Why Bonds Are Risky
Bondholders face three major risks:
A. Default Risk
1. There is no guarantee that a bond issue will make the promised payments.
2. Investors who are risk averse require some compensation for bearing risk;
the more risk, the more compensation they demand.
3. The higher the default risk the higher the probability that bondholders will
not receive the promised payments and thus, the higher the yield.
B. Inflation Risk
1. Bonds promise to make fixed-dollar payments, and bondholders are
concerned about the purchasing power of those payments.
2. The nominal interest rate will be equal to the real interest rate plus the
expected inflation rate plus the compensation for inflation risk.
3. The greater the inflation risk, the larger will be the compensation for it.
C. Interest-Rate Risk
1. Interest-rate risk arises from the fact that investors don’t know the holding
period yield of a long-term bond.
2. If you have a short investment horizon and buy a long-term bond you will
have to sell it before it matures, and so you must worry about what happens
if interest rates change.
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Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
3. Because the price of long-term bonds can change dramatically, this can be
an important source of risk.
Using FRED: Codes for Data in This Chapter
Data Series FRED Data Code
Threemonth Treasury bill rate TB3MS
Oneyear Treasury bill rate TB1YR
Twoyear Treasury constant maturity rate GS2
10year Treasury constant maturity rate GS10
30year Treasury constant maturity rate GS30
Fiveyear Treasury inflationindexed yield FII5
10year Treasury inflationindexed yield FII10
30year Treasury inflationindexed yield FII30
Consumer price index CPIAUCSL
Survey: expected inflation over 12 months MICH
Japan Treasury bill rates INTGSTJPM193N
Brazil Treasury bill rates INTGSTBRM193N
Terms Introduced in Chapter 6
capital gain
capital loss
consol or perpetuity
current yield
default risk
holding period return
inflation risk
inflation-indexed bonds
interest-rate risk
investment horizon
U.S. Treasury bill (T-bill)
yield to maturity
zero-coupon bond
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Chapter 06 – Bonds, Bond Prices, and the Determination of Interest Rates
Lessons of Chapter 6
1. Valuing bonds is an application of present value.
a. Pure discount or zero-coupon bonds promise to make a single payment on a
predetermined future date.
b. Fixed-payment loans promise to make a fixed number of equal payments at
regular intervals.
c. Coupon bonds promise to make periodic interest payments and repay the principal
at maturity.
d. Consols (perpetuities) promise to make periodic coupon payments forever.
2. Yields are measures of the return on holding a bond.
a. The yield to maturity is a measure of the interest rate on a bond. To compute it,
set the price of the bond equal to the present value of the payments.
b. The current yield on a bond is equal to the coupon rate divided by the price.
c. When the price of a bond is above its face value the coupon rate is greater than
the current yield, which is higher than the yield to maturity.
d. One-year holding period returns are equal to the sum of the current yield and any
capital gain or loss arising from a change in a bond’s price.
3. Bond prices (and bond yields) are determined by supply and demand in the bond
market.
a. The higher the price, the larger the quantity of bonds supplied.
b. The higher the price, the smaller the quantity of bonds demanded.
c. The supply of bonds rises when
i. Governments need to borrow more.
ii. General business conditions improve.
iii. Expected inflation rises.
d. The demand for bonds rises when
i. Wealth increases.
ii. Expected inflation falls.
iii. The expected return, relative to other investments, rises.
iv. The expected future interest rate falls.
v. Bonds become less risky, relative to other investments.
vi. Bonds become more liquid, relative to other investments.
4. Bonds are risky because of
a. Default risk: the risk that the issuer may fail to pay.
b. Inflation risk: the risk that the inflation rate may be more or less than expected,
affecting the real value of the promised nominal payments.
c. Interest Rate Risk: the risk that the interest rate might change, causing the bond’s
price to change.
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