64 Part One Value
bre44380_ch03_046-075.indd 64 09/30/15 12:47 PM
This is Fisher’s theory: A change in the expected inflation rate causes the same proportion-
ate change in the nominal interest rate; it has no effect on the required real interest rate. The
formula relating the nominal interest rate and expected inflation is
1 + rnominal = (1 + rreal) (1 + i)
where rreal is the real interest rate that consumers require and i is the expected inflation rate.
In our example, the prospect of inflation causes 1 + rnominal to rise to 1.03 × 1.05 = 1.0815.
Not all economists would agree with Fisher that the real rate of interest is unaffected by
the inflation rate. For example, if changes in prices are associated with changes in the level of
industrial activity, then in inflationary conditions I might want more or less than 103 apples in
a year’s time to compensate me for the loss of 100 today.
We wish we could show you the past behavior of interest rates and expected inflation.
Instead we have done the next best thing and plotted in Figure 3.8 the return on Treasury bills
(short-term government debt) against actual inflation for the United States, U.K., and Ger-
many. Notice that since 1953 the return on Treasury bills has generally been a little above the
rate of inflation. Investors in each country earned an average real return of between 1% and
2% during this period.
Look now at the relationship between the rate of inflation and the Treasury bill rate. Fig-
ure 3.8 shows that investors have for the most part demanded a higher rate of interest when
inflation was high. So it looks as if Fisher’s theory provides a useful rule of thumb for finan-
cial managers. If the expected inflation rate changes, it is a good bet that there will be a cor-
responding change in the interest rate. In other words, a strategy of rolling over short-term
investments affords some protection against uncertain inflation.
◗ FIGURE 3.7
The green line shows the real
yield on long-term TIPS issued
by the U.S. government. The
brown line shows the yield on
long-term nominal bonds.
1
2
3
4
5
6
Interest rat
e, %
22
21
0
10-year real interest rate
10-year nominal interest rate
Jan-03July-
03
Jan-04July-
04
Jan-05July-
05
Jan-06July-
06
Jan-07July-
07
Jan-08July-
08
Jan-09July-
09
Jan-10July-10Jan-11July-11Jan-12July-12Jan-13July-13Jan-14July-14
3-6 The Risk of Default
Corporate Bonds and Default Risk
Look at Table 3.6, which shows the yields to maturity on a sample of corporate bonds. Notice
that the bonds all mature in 2017, but their yields to maturity differ dramatically. With a yield
of over 20%, the bonds of Alpha Natural Resources appeared to offer a mouth-watering rate
of return. However, the company had been operating at a loss and had substantial debts. Inves-
tors foresaw that there was a good chance that the company would go bankrupt and that they
would not get their money back. Thus the payments promised to the bondholders represent a