Lecture 2 - Time Value Of Money Flashcards
Basic financial principle
A £ today is worth more than a £ in the future
Why?
- opportunity cost
- inflation
- uncertainty
Cash flows occurring in different time periods are not directly comparable. They need to be adjusted for the time value of money!
Present And future values
Future value (FV) is the amount to which an investment today - present value (PV) - will grow after earning interest (r) for a time period (t)
The growth depends on whether the investment earns:
- simple interest
Or
- compound interest
Simple interest
What is the future value of £100 that earns for 5 years 6% simple interest:
Year1) £100. 0.06 x 100= £6. £106
Year2) £106. 0.06 x 100 =£6. £112
Etc..
FV with simple interest
FV = PV x (1+r x t)
Compound interest
What is the future value of £100 that earns for 5 years 6% compound interest ?
Year1) £100. 0.06 x £100 =£6. £106
Year2) £106. 0.06 x £100 =£6.36. £112.36
Year3) £112.36. 0.06x£100=£6.74. £119.10
Etc
FV with annual compounding
FV = PV x (1 + r)power of t
FV with compound interest
FV = PV x (1 + r/n) power of n x t
Compounding N
- annual 1
- semi-annual. 2
- quarter. 4
- month 12
- week. 52
- day 365
FV with continuous compounding
Continuous compounding means that n becomes infinitely large. It turns out that the FV of an investment with continuous compounding is given by:
FV = PV x e (power of r x t)
E is known as Euler’s number & has a value of approximately 2.71828
The relation between FV & PV
Compounding:
- what is the future value of £1 invested today for t years if the interest rate is r?
Discounting:
- what is the present value of £1 that will be received after t year if the interest rate is r?
PV of annuities
PV = cash Payment x [1/r - 1/r x (1+r) t ]
For computing the FV of an annuity simply multiply its PV by (1 + r)t
If the first cash payment is today, the annuity is called ‘annuity due’
The PV (FV) of an annuity due is simply the PV (FV) of an ordinary annuity multiplied by (1+r)
Effective & percentage annual rates
Effective annual interest rate (EAR) is an interest rate annualised using compound interest
- 1 + EAR = (1 + r/n)n
Annual percentage rate (APR) is a short term rate annualised by multiplying the rate per period with the number of periods in a year
Nominal and real interest rates
Nominal interest rate is the rate at which money invested grow
Real interest rate is the rate at which the purchasing power of an investment grows
1 + real investment rate = 1 + nominal interest rate / 1 + inflation rate
Nominal (real) cash flows must be discounted at the nominal (real) rate