ADVANTAGES OF THE POTENTIAL PAYBACK PERIOD (PPP)
AND INTERNAL RATE OF RETURN (IRR)
IN STOCK EVALUATION AND INVESTMENT MANAGEMENT
I- DEFINITIONS
The Potential Payback Period (PPP) is a mathematical adjustment of the Price Earnings Ratio (PER) to incorporate earnings growth rate (“g”) and interest rate (“r”) in the stock evaluation process. It represents the time (in years) it takes for the buyer of a stock to "potentially recover" the stock purchase price through discounted future earnings.
Unlike the PER, which is a static measure as it captures the earnings of
a single year, the PPP dynamically measures – through the expected
earnings growth rate – the profit-making capacity (or earnings
potential) of a company over many years. This profit-making capacity of
a company determines the value of its stock.
Note: PER is a specific case of PPP. The PER indicates the number of
years of earnings needed to “recover” the stock price, assuming the
initial earnings remain constant over the years. On the other hand, the
PPP also indicates the number of years of profits needed to “recover”
the stock price but assumes a more general and realistic scenario where
future earnings will increase over the years. Additionally, PPP
replicates a more realistic environment by introducing an interest rate
to discount future earnings and compare them to the current stock
price.
The
Internal Rate of Return (IRR) is
the discount rate applied to future earnings over the PPP period to
equalize these earnings with the current stock price. IRR is thus a
derivative of PPP.
Demonstration of formulas at
https://www.stockinternalrateofreturn.com/Mathematics.html
II- ADVANTAGES OF PPP AND IRR
1- Rigorous adjustment of PER to take earnings growth rate into account
PPP, resulting from this adjustment, provides a more meaningful and
operational measure of stock "expensiveness." Stocks with seemingly
"prohibitive" PERs can become very attractive in terms of PPP,
especially when dealing with high-growth values.
There are empirical and approximate methods to adjust PER based on
earnings growth rate "g" such as the Price/Earnings-to-Growth Ratio
(PEG), which simply divides PER by "g" and favours stocks with a PEG
below 1. Through a slightly more complex formula, PPP moves from this
empirical and approximate approach to mathematical logic and precision.
The need to adjust PER is illustrated by the example of NVIDIA as we
wrote on 7 October 2023:
https://www.linkedin.com/feed/update/urn:li:activity:7116790087434035200/
2- Stock evaluation without PER
Since PPP apprehends a company's evolution over many (generally more
than 10) years, it remains meaningful and operational, whereas PER loses
its significance for a company experiencing temporary losses or making
profits close to zero for one or more years, as in the case of startups
or companies in a turnaround situation. PPP allows for meaningful
comparisons at any time between all companies, whether profitable or
making losses.
https://www.linkedin.com/feed/update/urn:li:activity:7144012724220436480/
3- Explanation and measurement of the impact of quarterly earnings revisions on stock prices
The value of a stock primarily reflects the profit-making capacity of a
company. The impact of quarterly earnings revisions on stock prices
actually reflects a reassessment of this profit-making capacity through
a revision of the earnings growth rate. Quarterly revision leads,
through extrapolation, to a revision of the earnings growth rate over a
period well beyond the quarter in question. A new earnings growth rate
immediately modifies the level of PPP, automatically resulting in an
adjustment of the stock price.
The stock market is highly sensitive to any change in the earnings
growth rate. It is not the growth rate itself (concept of "first
derivative" in physics) that matters most, but its acceleration or
deceleration (concept of "second derivative").
https://www.stockinternalrateofreturn.com/Earnings-Revisions.html
4- Refinement of stock selection models
As a synthetic and operational measure of stock value, PPP paves the way
for refining stock comparison and selection models. For example, a risk
factor can be introduced into such a model, establishing an inverse
correlation (entirely logical) between PPP and the risk factor. A
regression line can then be drawn, showing a quite understandable
decrease in PPP as risk increases. In other words, an investment must be
"recovered" more quickly as the environment becomes riskier. On the
other hand, IRR and risk vary in the same direction: higher
profitability is required with increasing risk.
https://www.stockinternalrateofreturn.com/Magnificent-Seven.html
5- Measurement of the impact of a change in interest rates on stock prices and establishment of a precise and novel link between stocks and bonds
The inverse relationship between interest rates and stock prices is
known intuitively and empirically. The PPP allows for the measurement of
the impact of a change in interest rates on the price of a stock.
The IRR, directly derived from PPP, measures the internal return of an
industrial or commercial operation that necessarily involves risk. This
return must be higher than that of a risk-free investment over an
equivalent period, namely a long-term government bond. The difference
between the IRR of a stock and the yield of a long-term government bond
represents the "risk premium" of that stock. This premium, which
practically ranges from 1 to 10%, varies inversely with the quality and
predictability of the company represented by the stock. In any case,
through the IRR of the stock, a precise and novel link is established
between the stock market and the bond market.
https://www.linkedin.com/feed/update/urn:li:activity:7134662603556950016/
6- Comparison of International Financial Markets
The scope of comparisons based on PPP can be extended to international
financial markets as a whole, which, in addition to differences in
average PERs, present differentials in the average earnings growth rate
and the interest rate on a risk-free long-term loan.
Starting from PPP, the IRR of each market is calculated. The difference
between the IRR and the risk-free long-term interest rate represents the
"risk premium," which is somewhat a safety margin for the investor. The
higher the "risk premium," the more attractive the market becomes. This
comparison of markets based on a synthetic indicator like the "risk
premium" can be an interesting tool for international capital
management.
https://www.linkedin.com/feed/update/urn:li:activity:7148362250381127681/
7- Rationality and Homogeneity of Financial Markets
PPP and IRR allow verifying the rationality and homogeneity of financial
markets. If one relies solely on PER to assess the "expensiveness" of
stocks, absurd orders of magnitude can be reached. Indeed, PER can reach
astronomical amounts when the earnings per share for the selected year
is close to 0, and it loses all meaning in the case of losses. On the
other hand, PPP and IRR, which integrate fundamental data over a longer
period, can be calculated significantly for any stock at any time, even
for companies in a turnaround situation involving temporary losses.
https://www.stockinternalrateofreturn.com/negative-earnings-per-share.html
In any case, PPP varies over a limited range of about 5 to 15 years,
corresponding to an IRR range of approximately 15 to 5% in the opposite
direction. These figures for PPP and IRR can be considered significant,
realistic, and credible due to their reasonable order of magnitude and
relative stability, demonstrating the rationality and homogeneity of
financial markets.
https://www.stockinternalrateofreturn.com/Genesis.html
Rainsy Sam
Investment manager
Former Cambodian Finance Minister