DuPont decomposition

Three companies each report a return on equity of 24%. On the screener they sit in a row, indistinguishable. But one earns that 24% by selling a branded product at a fat margin; the second earns exactly the same by running a thin margin at enormous speed, turning its capital over many times a year; and the third earns it by loading a mediocre business with debt until leverage magnifies an ordinary return into a striking one. Three identical numbers, three completely different machines - and one of them will fall apart in the first bad year while the other two hold. illustrative

A single ROE can never tell them apart, because a single number cannot show how it was made. That is what DuPont decomposition does. Written out, ROE is exactly net margin × asset turnover × leverage, and reading which of the three levers is doing the work is the single most revealing exercise in ratio analysis. It tells you not just how good the return is, but what kind of business you are holding, and where that return would break.

The decomposition is an identity - always true, by construction. Return on equity equals net profit over equity. Multiply that by sales over sales and by assets over assets, rearrange, and it becomes three fractions multiplied together: net profit over sales (the net margin, how profitable each sale is), sales over assets (the asset turnover, how hard the assets work), and assets over equity (the equity multiplier, how much leverage sits underneath). Nothing has been added; the same ROE has simply been broken into its parts. But those parts map onto the three ways a business can make money - charge more per sale, sell more per rupee of assets, or borrow - and each answers a different question about durability.

Read which lever is pulling. A high margin with modest turnover is the brand signature - the return is only as durable as the pricing power behind it. A thin margin with high turnover is the volume-operator signature - retail, distribution, commodities - where the return comes from recycling capital fast, and durability rests on operational discipline and scale. A high equity multiplier carrying an otherwise ordinary business is the leverage signature - the most fragile, because it has bought return with risk, and the risk shows up exactly when times turn hard, the leverage that can force selling at the very bottom. When you decompose an ROE, the first question is which lever dominates; the second is whether that lever can keep pulling.

Watch which lever moves. The split is even more useful across time than at a point. If ROE rises, ask which term rose: margin (better pricing or mix), turnover (assets working harder), or leverage (more debt). The first two are earned; the third is borrowed. When margin and turnover are flat and ROE still climbs, leverage is the only lever left, and it has been pulled - a company manufacturing a better-looking return by taking on risk, which should read as a caution, not a triumph.

The three-term version answers the durability question on its own. When you need to go deeper, the margin term itself splits further - into operating margin, the interest burden and the tax burden - a five-part decomposition that separates a genuinely more profitable operation from one that merely paid less tax this year. But start with the three levers; the extended form is a refinement, not a replacement.

Every sector has a characteristic DuPont signature - a typical shape of margin, turnover and leverage - and the shape tells you at a glance whether a company is normal for its industry or doing something unusual. The most important case is the one where the signature inverts the manufacturing instinct entirely.

The inversion to hold onto is the bank. For a manufacturer, an equity multiplier of six is a red flag - debt doing the work operations should. For a bank, a multiplier of twelve is not a warning at all; it is the entire business model, because a bank is funded by deposits and lends a multiple of its equity by design. A bank's DuPont ROE is dominated by leverage, and reading that leverage as danger - as you rightly would in a manufacturer - gets the bank exactly wrong. This is the same lesson the return-ratios module reached from another angle: the tool must be read against the business. DuPont does not tell you whether leverage is good or bad in the abstract; it tells you how much of the return leans on it, and you decide whether that lean is the model or the risk. For the cyclical, the caution is different - the margin lever is not stable, so any one year's decomposition reads where the cycle is, not what the business structurally is.

Do the arithmetic once, by hand, so the identity stops being abstract. Here are two years of a composite consumer-durables maker whose ROE has jumped from 16% to 24% - a rise the market has re-rated as proof of a quality compounder. Five lines from the statements settle whether that story is true. illustrative

Work down the table. Net margin: ₹80 on ₹1,000 is 8.0%; ₹104 on ₹1,300 is 8.0% - unchanged. Asset turnover: 1.11 then, 1.10 now - effectively flat. Equity multiplier: 1.80 then, 2.74 now - up sharply. Multiply the three back to confirm the identity holds: 0.08 × 1.11 × 1.80 = 16.0%; 0.08 × 1.10 × 2.74 = 24.2%. The arithmetic ties out, because an identity always does.

Now read what moved. ROE jumped eight points, and two of the three levers did not budge - the entire gain came from the equity multiplier. Look at why it rose: assets grew from ₹900 to ₹1,180 (funded by new debt) while equity actually fell from ₹500 to ₹430 - the fingerprint of a share buyback. So the "improving return" is neither better pricing nor better efficiency; it is more debt on a smaller equity base, exactly the leverage signature. The operations did not improve at all; the balance sheet simply got riskier.

That does not automatically make it a bad company - leverage funding genuinely high-returning expansion can be sensible, and a buyback at a low price creates value. But it completely changes what you are betting on. You are no longer betting on a widening moat; you are betting that a now-more-leveraged business can service materially more debt through whatever its cyclical end-markets throw at it. The DuPont split turned a comfortable "returns are improving" into the sharper, more honest question - can this business carry its debt through a downturn? The single rising ROE hid that question completely. The habit is to never accept a rising ROE as improvement until you have seen which lever raised it.

Set the three levers and watch the same ROE assemble three different ways. Push leverage up and the return rises - but so does the fragility. The same ROE earned through margin or turnover is operationally sound; the one built on debt is what a downturn breaks first.

DuPont tells you which lever is pulling, not whether it will keep pulling. It can show a return rests on a fat margin, but not whether the pricing power behind that margin is a durable moat or a temporary gift about to be competed away; it can show a return rests on high turnover, but not whether the operational edge producing it is defensible. The decomposition locates the source of the return; judging the durability of that source is a separate enquiry into competitive position that three numbers cannot settle.

Nor can it tell you, on its own, whether leverage is prudent or reckless - a high equity multiplier is the model for a bank and a warning for a manufacturer, and DuPont is silent on which it is looking at. You supply that judgement by knowing the business and asking whether the cash flows are steady enough to carry the debt through bad times, which is the leverage module's subject. And, like every ratio, DuPont inherits the honesty of its inputs: a margin flattered by a one-off gain, or an asset base shrunk by write-offs or kept off the books through leases, will point the levers in misleading directions. A turnover that looks impressive because assets were written down is not real efficiency. The decomposition is only as truthful as the margin, the assets and the equity that go into it - and whether those are truthful is a question for the forensics part, not for DuPont.

How it comes up. When ROE improves, a good analyst asks management to attribute the gain to the three levers rather than celebrate the headline: "ROE went from 18% to 25%. Can you break that into margin, asset turnover and leverage? How much is operating and how much is the higher debt and the buyback?" The question forces the decomposition into the open.

A good answer, verbatim-style.

"Roughly half the improvement is operating - margin is up about 150 basis points on mix, and asset turnover improved as the new lines filled. The other half is leverage: we raised debt to fund the expansion and bought back about 4% of equity, so the multiplier went up. We're comfortable with the debt because our cash flows are stable, but I'd be clear that not all of the ROE gain is operational."

It splits the rise into the three levers, quantifies each, and is honest that part of the gain is financial.

An evasive answer, verbatim-style.

"We're delighted with the improvement in ROE to 25%, which reflects the strength of our franchise and our disciplined execution. It's a testament to the quality of the business and gives us confidence in delivering superior returns going forward."

It attributes a leverage-driven gain to "franchise" and "quality" - margin-and-moat words - and never mentions the debt or the buyback that actually did the work. It is selling a financial-engineering result as an operating one. The follow-up that settles it is a single question - "how many basis points of the ROE gain came from margin, from turnover, and from the equity multiplier?" A rising ROE that management attributes to "quality" but will not split into levers is almost always a leverage story wearing a moat's clothes.

1. Treating equal ROEs as equal businesses. The same return can be margin-led, turnover-led or leverage-led - three different investments with three different risks. The decomposition, not the headline, tells them apart.

2. Cheering a rising ROE without splitting the rise. If margin and turnover are flat and ROE still climbs, leverage did it. A return improved by borrowing is riskier, not better.

3. Reading leverage the same way in every business. A high equity multiplier is a warning in a manufacturer and the normal model in a bank. DuPont quantifies the lean on leverage; the business decides whether that lean is danger or design.

4. Mistaking written-down assets for real efficiency. An asset turnover that looks high because the asset base was shrunk by write-offs is not operational excellence - check the denominator before crediting the turnover. And when a one-off is hiding in the margin, extend the split to separate operating margin from the interest and tax burdens.