L6. The time value of money Flashcards
1
Learning Outcomes
- interpret interest rates as required rates of return, discount rates or opportunity costs
- explain an interest as sum of a real risk-free rate and premiums that compensate investors for bearing distinct types of risk
- calculate and interpret the effective annual rate, given the stated annual interest rate and the frequency of compounding
- solve time value of money problems for different frequencies of compounding
- calculate and interpret the future value (FV) and present value (PV) of a single sum of money, an ordinary annuity, an annuity due, a perpetuity (PV only) and a series of unequal cash flow
- demonstrate use of a time in modeling and solving time value of money problems
Time value of money
Deals with equivalence relationships between cash flows with different dates
Interest rate
EG. if pay $9500 today, and receive $10,000 next year; interest rate or the required compensation stated as the rate of return is $500/$9500 = 0.0526 or 5.26%
Interest rate can be thought in 3 days
- Required rate of return; the minimum rate of return an investor must receive in order to accept the investment
- Discount rates; eg 5.26% is the rate at which we discounted that $10,000 future amount to find its value today
- Opportunity costs; value that investors forgo by choosing a particular course of action. Eg if decided to spend $9,500 today, he would have forgone earning 5.26% on the money.
To determine r, interest rate composed of a real risk-free interest rate plus a set of 4 premiums that are required returns or compensation for bearing distinct types of risks
r = Real risk-free interest rate + inflation premium + default risk premium + liquidity premium + maturity premium
(Market determined interest rate = real risk free rate + inflation premium + risk premiums for default risk, liquidity and maturity)
- Real risk free interest rate; single period interest rate for a completely risk-free security if no inflation were expected. Reflects time preferences of individuals for current vs future real consumption
- Inflation premium; compensates investors for expected inflation and reflects average inflation rate expected over maturity of debt. Inflation reduces purchasing power of a unit of currency. Sum of real risk free interest rate and inflation premium = nominal risk free interest rate
- Default risk premium; compensates investors for the possibility that borrower will fail to make a promised payment at contracted time and amount
- Liquidity premium; compensates investors for risk of loss relative to an investment’s fair value if investment needs to be converted to cash quickly (eg Tbills do not have liquidity premium because large amount can be bought and sold without affecting market price but small issuers’ bonds trade infrequently after they are issued = interest rate would include liquidity premium)
- Maturity premium; compensates investors for increased sensitivity of market value of debt to a change in market interest rates as maturity is extended
Relationship between initial investment, which earns rate of return and its future value
Initial investment (PV), earns rate of return (r) and its future value (FV) which will be received in N years or periods from today
EG. invest $100 (PV = $100), interest bearing bank account paying 5% annually (r=5%). At end of first year, you will have $105 (5% of 100 plus PV)
For N = 1, formula as below
FV = PV(1+r)
in eg. FV = 100(1+0.05)
FV = 100(1.05)
FV = $105
If N=2, FV = PV(1+r)
FV = 105(1+0.05)
FV = 110.25
In other words, the simple interest is $5 earned year on year. In 2 years, earn $10 simple interest from principal (100). The extra 0.25 is earned from the interest of 5% (0.05*5)
Compounding interest
Is the interest earned on interest. Importance of compounding interest increases with the magnitude of the interest rate
Eg. 100 invested today would worth about 13,150 after 100 years compounded annually at 5% but worth more than 20 million if compounded annually over the same period at 13%
FV = PV(1+r)^n
*if N is in months, rate need to be monthly interest rate
Use of BA calculator to find answer (FV of single cash flow)
EG.
PV = 5 million
R = 7% annually
N = 5 years
What is FV?
Always 2nd FV to clear previous records, check RCL to see if all functions cleared
Key 5,000,000 and press PV
Key 7 and press I/Y
Key 5 and press N
Key CPT FV to find FV
Ans should be 7,012,758.65.
Examining payment interest more than a year
Many banks offer monthly interest rate that compounds 12 times a year IE monthly referred to stated annual interest rate or quoted interest rate
Eg. bank pays CD 8% compounded monthly; stated annual interest rate equals the monthly interest rate multiplied by 12. Monthly interest rate = 0.08/12 = 0.67% therefore it means (1+0.0067)^12 = 1.083
FV(n) = PV (1 + rs/m)^mN
where rs = stated annual interest rate
m = compounding periods per year
n = number of years
Use of BA calculator to find answer (Non annual Compounding)
EG.
CD offers 2 year maturity, stated annual interest rate of 8 percent compounded quarterly
PV = 10,000
What will the CD be worth at maturity?
Key 10,000 and press PV
Key 8/4 and press I/Y (8% divide by 4 periods; quarterly)
Key 4*2 and press N (4 periods x 2 years)
Key CPT FV to find FV
Ans should be 11,716.59
Use of BA calculator to find answer (Non annual Compounding)
EG
Australian bank offers to pay 6% compounded monthly
PV = 1,000,000
What is the FV?
Key 1,000,000 and press PV
Key 6/12 and press I/Y (6% divided by 12 periods; monthly)
Key 12*1 and press N (12 periods x 1 year)
Key CPT FV to find FV
Ans should be 1,061,677.81
Continuous compounding
Number of compounding periods per year becomes infinite, then interest is said to compound continuously
FV(n) = PVe^rsN
where e^rs^n is the transcendental number e=2.7182818 raised to the power rsN. On calculator it is e^x
Use of BA calculator to find answer (Continuous compounding)
PV = 10,000
8% compounded continuously for 2 years
FV(n) = PVe^rsN
= 10,000e^(0.08x2)
Type 0.08 x 2 = 0.16
Type 2nd LN 0.16 = 1.17
Type 10,000 x 1.17
Ans should be 11,735.11
Effective annual rate (EAR)
The amount of which a unit of currency will grow in a year with interest on interest included
EAR = (1 + periodic interest rate) ^m - 1
The periodic interest rate is the stated annual interest rate divided by m
or
EAR = e^rs - 1
Practice qns for EAR
1) Stated annual interest rate is 12.75%. If frequency of compounding is monthly, the EAR is?
EAR = (1 + periodic interest rate) ^m - 1
EAR = ( 1 + 0.1275/12)^12 - 1
= 13.52%
2) If the stated annual interest rate is 9% and the frequency is compounding daily, the EAR is?
EAR = (1 + periodic interest rate) ^m - 1
EAR = (1+ 0.09/365)^ 365 - 1
= 9.42%
Practice Qns for continuous compounding
Given a 1,000,000 investment for 4 years with a stated annual rate of 3% compounded continuously, the difference in its interest earnings compared with the same investment compounded daily is?
When compounded continuously; FV(n) = PVe^rsN PV = 1,000,000 rsN = 0.03 x 4 = 0.12 Type 0.12 2nd LN Type x 1,000,000 = 1,127,496.85 Interest = 1,127,496.85 - 1,000,000 = 127,496
When compounded daily; FV(n) = PV (1 + rs/m)^mN Type 1,000,000 PV Type 3/365 I/Y Type 365*4 N FV = 1,127,491.29 Interest = 1,127,491.29 - 1,000,000 = 127,491
Difference in interest = 127,496 - 127,491 = 5.56
Series of cash flow
- Annuity; finite set of level sequential cash flows
- Ordinary annuity; first cash flow that occurs one period from now (indexed at t = 1)
- Annuity due; first cash flow that occurs immediately (indexed at t = 0)
- Perpetuity; set of level near-ending sequential cash flows, with the first cash flow occurring one period from now
Equal cash flow - General future value annuity
FV(n) = A [ {(1+r)^N - 1} / r]
- Eg if 5% ordinary annuity annually, deposits of 1,000 for 5 years
(1+r)^N - 1 / r
(1 + 0.05)^5 - 1 / 0.05 = 5.525641
A x 5.525641 = 1000 x 5.525641 = 5,5525.63
- Eg. if 9% ordinary annuity annually, deposits 20,000 for 30 years
(1+r)^N - 1 / r
(1+0.09)^30 - 1/0.09 = 136.3075385
A x 136.3075385 = 20000 x 136.3075385 = 2,726,150.771