The third model was the payback, a favorite of business in the 1960’s and used at
least half of the time by 74.5% of the respondents. Fourth in popularity was the
discounted payback model, used at least half of the time by 56.7% of the companies.
Finally, at least half time usage was reported for the last three models as follows:
profitability index ranks fifth at 43.9%, followed by accounting rate of return at 33.3%
and finally, modified internal rate of return (MIRR) at 21.9%. Examination of within
model proportions for profitability index, accounting rate of return, and modified internal
rate of return reflect chi-squared significance at the 1% level, while the proportion
distributions for payback are chi-squared significant at the 5% level. The only model that
is not chi-squared significant when subdivided by the size of the capital budget is
discounted payback. Payback and profitability index are more frequently used by firms
with smaller capital budgets, while modified internal rate of return appears to be used
more frequently by firms with capital budgets in the range of $100-$500 million.
Modified internal rate of return is the least popular of all discounted and non-
discounted models. Some argue MIRR is superior to IRR because it allows the manager
to adjust the discount rate of intermediate term cash flows to better match a realistic
return for the cash flows. Samuel C. Weaver, Director of Financial Planning and
Analysis of Hershey Foods, commented at the 1988 FMA meeting (Financial
Management Panel Discussion; 1989),