1. Understanding the Concept of Present Value

2. Interest Rates, Compounding, and Present Value
In economics, an interest rate is known as the yield to maturity.
Compounding is the process that gives us the value of a sum invested over time at a positive rate of interest.
Present value is the process that tells us how much an expected future payment is worth today.

3. Compounding
Assume you have $1 which you place in an account paying 10% annually.
How much will you have in one year, two years, etc?
An amount of $1 at 10% interest
Year n
$ $ $ $1(1 + i)n
Formula: FV = PV(1 + i)

4. Compounding over Time Extending the formula over 2 years 3 years
FV = PV(1 + i) (1 + i) or FV = PV(1 + i)2
3 years
FV = PV(1 + i) (1 + i) (1 + i) = PV(1 + i)3
n years
FV = PV(1 + i)n

5. Present Value
Present value tells us how much an expected future payment is worth today.
Alternatively, it tells us how much we should be willing to pay today to receive some amount in the future.
For example, if the present value of $1.10 at an interest rate of 10% is $1, we should be willing to spend $1 today to get $1.10 next year.

6. Present Value Formula
The formula for present value can be found by rearranging the compounding formula.
FV = PV(1 + i) solve for PV
FV/(1 + i) = PV

7. Present Value over Time
Extending the formula over 2 years
FV = PV(1 + i)2
PV = FV/(1 + i)2
3 years
FV = PV(1 + i)3
PV = FV/(1 + i)3
n years
FV = PV(1 + i)n
PV = FV/(1 + i)n

8. Things to Notice
An increase in the interest rate causes present value to fall.
Higher rates of interest mean smaller amounts can grow to equal some fixed amount during a specified period of time.
A decrease in the interest rate causes present value to rise.
Lower rates of interest mean larger amounts are needed to reach some fixed amount during a specified period of time.

9. Example:
How much must I invest today to get $10,000 in five years if interest
rates are 10%?
PV = FV/(1 + i)n
PV = $10,000/( )5 = $10,000/ = $6,209.2
rates are 5%?
PV = $10,000/( )5 = $10,000/ $7,835.15

10. More Things to Notice Present value is always less than future value.
(1 + i)n is positive so FV/(1 + i)n < FV
In addition, PV4 < PV3 < PV2 < PV1
(1 + i)1 < (1 + i)2
The longer an amount has to grow to some fixed future amount, the smaller the initial amount needs to be.

11. Time Value of Money
The longer the time to maturity, the less we need to set aside today. This is the principal lesson of present value. It is often referred to as the “time value of money.”

12. Example:
If I want to receive $10,000 in 5 years, how much do I have to invest
now if interest rates are 10%?
$10,000 = PV( )5
$10,000/ = $
If I want to receive $10,000 in 20 years, how much do I have to invest
$10,000 = PV( )20
$10,000/6.7275= $

13. Yield to Maturity
Yield to maturity is the interest rate that equates the present value of payments received from a debt instrument with its value today.
Yield to maturity can be calculated using the present value formula.
PV = FV/(1 + i)
i = FV - PV/PV

14. Simple Example: PV = FV/(1 + i) PV(1 + i) = FV PV + PVi = FV

15. Relationship between Yield to Maturity and Price
Yields to maturity on a 10% coupon rate bond with a face value
of $1000 maturing in 10 years
Price of Bond Yield to Maturity

16. Relationship between Yield to Maturity and Price
Three interesting facts:
Price and yield are negatively related.
When the bond is at par, yield equals coupon rate.
Yield is greater (less than) than the coupon rate when the bond price is below (above) par value.

17. Current Yield
In more complicated cases, yield to maturity can be difficult to calculate. Tables are available that can be used. And, of course, calculators do a fine job.
There are also simple formulas that can approximate yield to maturity such as current yield.

18. Current Yield
Current yield is an approximation for yield to maturity that is used to calculate the interest rate on a bond quickly.
Formula:
Current yield = Coupon/Bond Price

19. Inverse Relationship
We can use the current yield formula to see clearly the inverse relationship between interest rates and bond prices.
Current yield = Coupon/Bond Price
The coupon is a fixed payment, it does not change. Therefore, if yields rise, bond prices must fall, and if yields fall, bond prices must rise.

20. Intuition
Assume you buy a $1,000 bond today with a fixed coupon of $100. You are receiving a 10% return. Let a year pass, and you find you want to sell you bond. You call your broker and say, “Sell!” Your broker sighs and tells you that bonds just like yours now yield 12%. What price can you expect to receive?

21. Example Use the current yield formula:
0.12 = $100/PB
0.12PB = $100
PB = $100/.12 = $833.33
You must reduce your price until $100 represents a 12% rate of return.

22. The Behavior of Interest Rates
The Bond Market Model

23. Understanding Interest Rates
Economists use three different models to explain how interest rates are determined.
The bond market model
The money demand/money supply model
The loanable funds model

24. The Bond Market Model
The bond market model is useful because of the issues that can be considered within its framework.
The impact of changes in----
Wealth
Expected interest rates or expected return
Expected inflation
Riskiness of bonds relative to other assets
Liquidity of bonds relative to other assets

25. The Bond Market Model
The bond market can be modeled using the concepts of demand and supply.
The demand for bonds is determined by individuals and institutions who wish to hold their wealth in bonds.
The supply of bonds is provided by institutions that issue bonds to raise funds.

26. The Demand for Bonds
The demand for bonds comes from savers, people who have funds in excess of their spending needs.
They are willing to hold bonds for two reasons:
Interest earned
Potential capital gains

27. Bond Demand Rate of return
According to the asset theory of demand, people compare one asset relative to another and choose the one that best suits their needs.
As the opportunity cost of an asset increases, people find it increasingly unattractive.

28. Opportunity Cost
The opportunity cost of an asset is defined as the difference between the rate of return received by the asset and the rate of return on an alternative asset.
When bond yields are high, people prefer bonds because the opportunity cost of holding other assets is high.
When bond yields are low, people prefer other assets because the opportunity cost of holding bonds is high.

29. Bond Demand
Investors who demand bonds based on opportunity cost considerations prefer to buy when interest rates are high and sell when interest rates are low.

30. Bond Demand Speculation
When choosing an asset, investors also consider risk.
Interest rate risk occurs when the market value of a bond falls because interest rates rise.
As we have seen, the existence of interest rate risk means investors face the possibility of capital losses when interest rates rise and capital gains when interest rates fall.

31. Speculation
Investors who speculate in the bond market prefer to buy when interest rates are high and sell when interest rates are low.
When interest rates are high, people expect them to fall. As they fall, bond prices rise, yielding a capital gain.
When interest rates are low, people expect them to rise. As they rise, bond prices fall, diminishing capital gains or yielding a capital loss.

32. Bond Demand
Both the opportunity cost motive and the speculative motive result in investors demanding bonds when interest rates are high and selling bonds when interest rates are low.

33. The Demand Curve for Bonds
Let r = RET = (F - P)/P
If F = $1,000 and P = $950, r = 5.26%
If F = $1,000 and P = $900, r = 11.1%
High bond prices are associated with low interest rates.
Low bond prices are associated with high interest rates.

34. The Demand Curve for Bonds
Price
Interest
Rate
When bond prices are high,
interest rates are low, and
bond demand is low.
When bond prices are low,
interest rates are high, and
bond demand is high.
ilow
PBhigh
PBlow
ihigh
Demand
QDlow
QDhigh

35. Bond Supply
The supply of bonds comes from institutions, governments (domestic and foreign), and businesses.
The quantity of bonds supplied depends in part on the interest rate bond suppliers must pay to attract funds.
As interest rates increase, the quantity supplied falls.
As interest rates decrease, the quantity supplied rises.

36. The Supply Curve for Bonds
Price
Interest
Rate
Supply
As bond prices rise, bond yields
fall, and quantity supplied rises.
As bond prices fall, bond yields
rise, and quantity supplied falls.
ilow
PBhigh
PBlow
ihigh
QSlow
QShigh

37. Equilibrium
Equilibrium is a state of rest. Either there are no forces causing change or there are equal opposing forces.
In the bond market, equilibrium occurs when the quantity of bonds demanded just equals the quantity of bonds supplied.

38. Equilibrium & Disequilibrium
Bond
Price
Interest
Rate S
Excess supply occurs when
bond prices are high and interest
rates are low.
Excess demand occurs when
bond prices are low and interest
rates are high. A B
ilow
PBhigh E
PBeq
ieq
ihigh
PBlow F G D

39. Disequilibrium Excess Supply Excess Demand
More people want to sell bonds than want to buy them.
Bond prices fall and interest rates rise.
Excess Demand
More people want to buy bonds than want to sell them.
Bond prices rise and interest rates fall.

40. Mechanics of an Increase in Demand
Bond
Price
Interest
Rate S b
Increases in bond demand cause
bond prices to rise and bond
yields to fall. P2 i1 a P1 i2 D2 D1
Q1 Q2

41. Mechanics of a Decrease in Demand
Bond
Price
Interest
Rate S
Decreases in bond demand cause
bond prices to fall and bond
yields to rise. a P1 i2 b P2 i1 D1 D2
Q2 Q1

42. Shifts in the Demand for Bonds
According to the asset theory of demand, changes in bond demand are caused by changes in---
Wealth
Expected return on bonds relative to expected returns on other assets
Expected riskiness of bonds relative to other assets
Liquidity of bonds relative to other assets.

43. Bond Demand and Wealth
Wealth is defined as a stock of assets that produce income. Wealth is not income.
In a business cycle expansion, wealth grows, causing the demand for bonds to rise and the demand curve to shift to the right.
In a business cycle contraction, wealth shrinks, causing the demand for bonds to fall and the demand curve to shift to the left.

44. Bond Demand and Expected Returns: Bonds
Higher expected interest rates in the future decrease the demand for long-term bonds and shift the demand curve to the left.
Lower expected interest rates in the future increase the demand for long-term bonds and shift the demand curve to the right.

45. Returns on Different Maturity 10% Coupon Rate Bonds
Term Initial i Initial P New i New P
30 10% %
20 10% %
10 10% %
5 10% %
1 10% %

46. Bond Demand and Expected Returns: Other Assets
Higher expected returns on other assets relative to bonds cause bonds to become less attractive and the bond demand curve shifts left.
Lower expected returns on other assets relative to bonds cause bonds to become more attractive and the bond demand curve shifts right.

47. Bond Demand and Expected Returns: Inflation
An increase in the expected rate of inflation will cause the demand for bonds to decline and the demand curve to shift to the left.
A decrease in the expected rate of inflation will cause the demand for bonds to increase and the demand curve to shift to the right.

48. Bond Demand and Risk
An increase in the riskiness of bonds causes the demand for bonds to fall and the demand curve to shift to the left.
An increase in the riskiness of other assets causes the demand for bonds to rise and the demand curve to shift to the right.

49. Bond Demand and Liquidity
Increased liquidity of bonds results in an increased demand for bonds and the demand curve shifts right.
Increased liquidity of other assets results in a decreased demand for bonds and the demand curve shifts left.

50. Bond Demand and Liquidity
Increased liquidity of bonds results in an increased demand for bonds and the demand curve shifts right.
Increased liquidity of other assets results in a decreased demand for bonds and the demand curve shifts left.

51. Mechanics of an Increase in Supply
Bond
Price
Interest
Rate S1 S2
An increase in the supply of bonds
causes bond prices to fall and bond
yields to rise. a i2 P1 b P2 i1 D
Q1 Q2

52. Mechanics of an Decrease in Supply
Bond
Price
Interest
Rate S1 S2
A decrease in the supply of bonds
causes bond prices to rise and bond
yields to fall. b i1 P2 a P1 i2 D
Q2 Q1

53. Shifts in Supply
Shifts in the supply curve for bonds are caused by changes in….
The expected profitability of investment opportunities
Expected inflation
Government activities

54. Shifts in the Supply of Bonds
Expected Profitability of Investment Opportunities
When an economy is growing rapidly, there are many profitable investment opportunities. The supply of bonds increases and the supply curve shifts to the right.
When an economy is contracting, there are fewer profitable opportunities. The supply of bonds decreases and the supply curve shifts left.

55. Shifts in the Supply of Bonds
Expected Inflation
An increase in expected inflation causes the supply of bonds to increase and the supply curve to shift right.
Inflation causes the real cost of borrowing to fall.

56. Shifts in the Supply of Bonds
Government Activities
Higher government deficits increase the supply of bonds, causing the supply curve to shift right.
Reductions in government deficits decrease the supply of bonds, causing the supply curve to shift left.

57. Real and Nominal Interest Rates
Nominal interest rate is the rate of interest that makes no allowance for inflation.
The real interest rate is the rate of interest that is adjusted for expected changes in the price level.
It more accurately reflects the true cost of borrowing and lending.

58. Fisher Equation
The Fisher equation states that the nominal interest rate equals the real interest rate plus the expected rate of inflation
in = ir + p
Rearranging terms we find:
ir = in - p

59. Logic behind the Inflation Premium
Lenders want to be compensated for the loss in buying power due to inflation.
Buyers understand that they will be repaying debt with dollars that buy less.
The interest rate must reflect these facts.

60. The Fisher Effect When expected inflation increases:
Bond supply increases and the supply curve shifts right.
Bond demand decreases and the demand curve shifts left.
As a result, bond prices fall and interest rates rise.
When expected inflation rises, interest rates rise. This is the Fisher Effect.

61. The Fisher Effect
Bond
Price
Interest
Rate S
Your turn a P i D Q