This chapter explains the algebra of the time value of money and net present
value. NPV depends upon the size, timing, and riskiness of expected cash flows,
which is consistent with the maximization of shareholder wealth discussed in
Chapter 1.
There are three ways to compute time-value-of-money problems: with a financial
calculator (or spreadsheet), with formulas, and with time value factor tables. A
good understanding of the formulas is necessary to value more complex cash flow
streams in later chapters; however, the understanding of financial calculators and
spreadsheets is just as important.
Lecture Tip: Many students find the phrases “time value of money” and “a
dollar today is worth more than a dollar later” a bit confusing. In some ways it
might be better to say the “money value of time.”
Indeed, much of the terminology surrounding exchanges of money now for
money later is confusing to students. For example, present value as the name for
money paid or received earlier in time and future value as the name for money
paid or received later in time are a constant source of confusion. How, students
ask, can money to be paid next year be a “present” value; how can money
received today be a “future” value?
They must be made aware that we mean earlier money and later money.
Many students never fully comprehend that present value, future value, interest
rates, and interest rate factors are simply a convenient means for communicating
the terms of exchange for what are essentially different kinds of money. One way
to emphasize both the exchange aspect of the time value of money and that
present dollars and future dollars are different kinds of money is to compare them
to U.S. dollars and Canadian dollars.
Both are called dollars, but they are not the same thing. And just as U.S.
dollars rarely trade 1 to 1 for Canadian dollars, neither do present dollars trade
1 to 1 for future dollars (except if r=0). Just as there are exchange rates for U.S.
dollars into Canadian dollars and vice-versa, so present value factors and future
value factors represent exchange rates between earlier money and later money.
Also, the same reciprocity that exists between the foreign exchange rates exists
between future value and present value interest factors.
1. Valuation: The One-Period Case
Slide 4.3 The One-Period Case
Slide 4.4 Future Value
If you invest $C today at an interest rate of r, you will have $C +
$C(r) = $C(1 + r) in one period.
The general form is: FV = C0×(1 + r)
where
r is the interest rate per period (or opportunity cost)