Introduction This chapter introduces the concepts and skills necessary to understand the time value of money and its applications.
Simple and Compound Interest Simple Interest –Interest paid on the principal sum only Compound Interest –Interest paid on the principal and on prior interest that has not been paid or withdrawn
tto denote time PV 0 = principal amount at time 0 FV n = future value n time periods from time 0 PMTto denote cash payment PVto denote the present value dollar amount Tto denote the tax rate Ito denote simple interest ito denote the interest rate per period nto denote the number of periods Notation
Future Value of a Cash Flow At the end of year n for a sum compounded at interest rate i is FV n = PV 0 (1 + i) n Formula In Table I in the text, (FVIF i,n ) shows the future value of $1 invested for n years at interest rate i: FVIF i,n = (1 + i) n Table I When using the table, FV n = PV 0 (FVIF i,n )
Tables Have Three Variables Interest factors (IF) Time periods (n) Interest rates per period (i) If you know any two, you can solve algebraically for the third variable.
Present Value of a Cash Flow PV 0 = FV n  Formula PVIF i, n = Table II PV 0 = FV n (PVIF i, n ) Table II 1 (1 + i) n
Example Using Formula What is the PV of $100 one year from now with 12 percent interest compounded monthly? PV 0 = $100 1/(1 +.12/12) (12 1) = $100 1/(1.126825) = $100 (.88744923) = $ 88.74
Example Using Table II PV 0 = FV n (PVIF i, n ) = $100(.887) From Table II = $ 88.70
Annuity A series of equal dollar CFs for a specified number of periods Ordinary annuity is where the CFs occur at the end of each period. Annuity due is where the CFs occur at the beginning of each period.
FVIFA i, n = Formula for IF FVAN n = PMT(FVIFA i, n ) Table III Future Value of an Ordinary Annuity (1 + i) n – 1 i
Derivation of the FVAN formula(1) The FVAN formula is a geometric series because each term on the right side is equal to the previous term multiplied by a common factor: 1/(1+i). Multiply both sides of the equation above by the common factor to create a second equation.
Derivation of the FVAN formula(2) Subtract this new equation from the original equation on the previous slide. The result: Solve for FVAN.
Present Value of an Ordinary Annuity PVIFA i, n = Formula PVAN 0 = PMT( PVIFA i, n ) Table IV 1 (1 + i) n 1 – i
Annuity Due Future Value of an Annuity Due –FVAND n = PMT(FVIFA i, n )(1 + i) Table III Present Value of an Annuity Due –PVAND 0 = PMT(PVIFA i, n )(1 + i) Table IV
Other Important Formulas Sinking Fund –PMT = FVAN n /(FVIFA i, n ) Table III Payments on a Loan –PMT = PVAN 0 /(PVIFA i, n ) Table IV Present Value of a Perpetuity –PVPER 0 = PMT/i
Interest Compounded More Frequently Than Once Per Year Future Value nm nom 0n m i 1PVFV )( += Present Value ) nm m i nom (1 + FV n PV 0 = m= # of times interest is compounded n = # of years
Interest Compounded More Frequently than Once Per Year Texas Instruments BA II Plus Calculator – set the number of compounding periods to 12 per year: 2 nd, P/Y,, 12, ENTER, CE/C, CE/C When finished: 2 nd, CLR TVM And, reset compounding to once per year: 2 nd, P/Y,, 1, ENTER, CE/C, CE/C
Effective Annual Rates A nominal rate of interest (or Annualized Percentage Rate) is found by multiplying the rate charged or paid per period by the number of periods during the year. This rate does not include the effect of compounding of interest at the end of each period of the year.
Effective Annual Rates For comparison purpose, we need an effective annual rate that includes the effect of compounding. Solve for the rate that gives the same effect with once per year compounding as the APR gives with more frequent compounding than annual.
Effective Annual Rates If compounding is done continuously,
Compounding and Effective Rates Rate of interest per compounding period i m = (1 + i eff ) 1/m – 1 Effective annual rate of interest i eff = (1 + i nom /m) m – 1