Yesterday I discussed Michael Mauboussin’s December 2007 Mauboussin on Strategy, “Death, Taxes, and Reversion to the Mean; ROIC Patterns: Luck, Persistence, and What to Do About It,” (.pdf) about Mauboussin’s research on the tendency of return on invested capital (ROIC) to revert to the mean.
Mauboussin’s report has three broad conclusions, with significant implications for modelling:
- Reversion to the mean is a powerful force. As has been well documented by numerous studies, ROIC reverts to the cost of capital over time. This finding is consistent with microeconomic theory, and is evident in all time periods researchers have studied. However, investors and executives should be careful not to over interpret this result because reversion to the mean is evident in any system with a great deal of randomness. We can explain much of the mean reversion series by recognizing the data are noisy.
- Persistence does exist. Academic research shows that some companies do generate persistently good, or bad, economic returns. The challenge is finding explanations for that persistence, if they exist.
- Explaining persistence. It’s not clear that we can explain much persistence beyond chance. But we investigated logical explanatory candidates, including growth, industry representation, and business models. Business model difference appears to be a promising explanatory factor.
How to identify ROIC persistence ex ante
The goal of the investor is to identify businesses with future, sustainable, high ROIC. Mauboussin explores three variables that might be predictive of such persistent high ROIC: corporate growth, the industry in which a company competes, and the company’s business model.
The bad news about growth, especially for modelers, is it is extremely difficult to forecast. While there is some evidence for sales persistence, the evidence for earnings growth persistence is scant. As some researchers recently summarized, “All in all, the evidence suggests that the odds of an investor successfully uncovering the next stellar growth stock are about the same as correctly calling coin tosses.” 16
Mauboussin finds that industries that are overrepresented in the highest return quintile throughout the measured period are also overrepresented in the lowest quintile. Those industries include pharmaceuticals/biotechnology and software. He concludes that positive, sustainable ROICs emerge from a good strategic position within a generally favorable industry.
This is perhaps the most useful and interesting variable considered by Mauboussin. He relates Michael Porter’s two sources of competitive advantage – differentiation and low-cost production – to ROIC by breaking ROIC into its two prime components, net operating profit after tax (NOPAT) margin and invested capital turnover (NOPAT margin equals NOPAT/sales, and invested capital turnover equals sales/invested capital. ROIC is the product of NOPAT margin and invested capital turnover.):
Generally speaking, differentiated companies with a consumer advantage generate attractive returns mostly via high margins and modest invested capital turnover. Consider the successful jewelry store that generates large profits per unit sold (high margins) but doesn’t sell in large volume (low turnover). In contrast, a low-cost company with a production advantage will generate relatively low margins and relatively high invested capital turnover. Think of a classic discount retailer, which doesn’t make much money per unit sold (low margins) but enjoys great inventory velocity (high turnover). Exhibit 8 consolidates these ideas in a simple matrix.
Not surprisingly, this group outperformed the broader sample on both NOPAT margin and invested capital turnover, but the impact of margin differential (2.4 times the median) was greater on ROIC than the capital turnover differential (1.9 times). While equivocal, these results suggest the best companies may have a tilt toward consumer advantage.
An analysis of the poor performers reveals that they posted NOPAT margins and invested capital turnover “symmetrical” with the high-performing companies i.e. below the full sample’s median.
Our search for factors that may help us anticipate persistently superior performance leaves us little to work with. We do know persistence exists, and that companies that sustain high returns over time start with high returns. Operating in a good industry with above-average growth prospects and some consumer advantage also appears correlated with persistence. Strategy experts Anita McGahan and Michael Porter sum it up: 22
It is impossible to infer the cause of persistence in performance from the fact that persistence occurs. Persistence may be due to fixed resources, consistent industry structure, financial anomalies, price controls, or many other factors that endure . . . In sum, reliable inferences about the cause of persistence cannot be generated from an analysis that only documents whether or not persistence occurred.
More to come.