Why this is mistaken
The control-panel model
The mistake sees three factors and imagines three unrelated dials. Turn each up, and ROE must improve.
Why it fails
Margin and turnover can reflect a business-model tradeoff. Price changes can affect volume; inventory cuts can affect service; asset reductions can constrain capacity. More leverage can change interest cost, liquidity, investment choices, and risk, which can later alter both margin and turnover.
The terms are separable in an identity, not necessarily in the business.
How to diagnose it
Describe one action that raises a component and then trace a plausible effect on the other two. A response that treats the remaining columns as fixed reveals the misconception.
Corrective approach
Use DuPont first for mathematical attribution. For any proposed change, add an operational and financing mechanism, a time horizon, expected interactions, and evidence that would reveal an adverse tradeoff.
When this mistake may appear
- A DuPont table displays three columns as separate performance targets.
- A recommendation says to increase all components without a mechanism.
Your work may contain this mistake if:
- Recommends higher prices, lower assets, and more leverage without considering volume, capacity, cost, liquidity, or risk.
- Treats algebraic cancellation as evidence that the business drivers do not interact.