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Suppose that the interest rate (r) is such that the present value of receiving $V2 in t2 years from

now is the same as the present value of receiving $V1 in t1 years from now, t2 > t1. Assume
that interest is compounded annually.
a. Show that V2 > V

User Allen Koo
by
7.6k points

1 Answer

2 votes

a. It is shown that
\(V2\) is greater than
\(V1\).

b. The present value of receiving
\(V₂\) at
\((2+k)\) years from now is equal to the present value of receiving
\(V₁\) at
\((t+k)\) years from now for any value of
\(k\).

How did we arrive at this assertion?

The formula for the present value (PV) of a future amount (FV) compounded annually is given by:


\[PV = (FV)/((1 + r)^n)\]

where:

-
\(PV\) is the present value,

-
\(FV\) is the future value,

-
\(r\) is the interest rate per period, and

-
\(n\) is the number of periods.

To show that
\(V_2 > V_1\)

We are given that the present value of receiving
\(V_2\) in 12 years is the same as the present value of receiving
\(V_1\) in 4 years.


\[ (V_2)/((1 + r)^(12)) = (V_1)/((1 + r)^4) \]

Cancel out the denominators and rearrange the equation:


\[ V_2 = V_1 \cdot (1 + r)^(12-4) \]


\[ V_2 = V_1 \cdot (1 + r)^8 \]

Since
\( (1 + r)^8 > 1 \) (because
\( r > 0 \)), it follows that
\( V_2 > V_1 \).

(b) Show that the present value of receiving
\(V_2\),
\((2+k)\) years from now, is also equal to the present value of receiving
\(V_1\),
\((t+k)\) years from now, for any value of
\(k\).

We are asked to show that:


\[ (V_2)/((1 + r)^(2+k)) = (V_1)/((1 + r)^(t+k)) \]

Cancel out the denominators and rearrange the equation:


\[ V_2 = V_1 \cdot \left( ((1 + r)^(t+k))/((1 + r)^(2+k)) \right) \]

Simplify the expression:


\[ V_2 = V_1 \cdot (1 + r)^(t-k) \]

This shows that the present value of receiving
\(V_2\)
\((2+k)\) years from now is equal to the present value of receiving
\(V_1\) \((t+k)\) years from now for any value of
\(k\).

Therefore, the present value of receiving
\(V₂\) at
\((2+k)\) years from now is equal to the present value of receiving
\(V₁\) at
\((t+k)\) years from now for any value of
\(k\).

Complete question:

3. Suppose that the interest rate (r) is such that the present value of receiving $V2 in 12 years from now is the same as the present value of receiving $
V_1 in four years from now, 12>4. Assume that interest is compounded annually.

(a) Show that V₂ >
V_1.

(b) Show that the present value of receiving $V2, (2+k) years from now is also equal to the present value of receiving $V₁, (t+k) years from now for any value of k. (That is, it is the absolute difference between time periods that matter.)

User Julien Poulin
by
8.9k points