The before-and-after method estimates lost profits by projecting a business’s own pre-harm performance forward into the loss period, while the yardstick method estimates them by benchmarking the business against comparable companies, sibling locations, or industry data — and the right choice turns on whether the plaintiff has a clean, representative track record of its own to build from. When a company has a stable operating history that the wrongful act interrupted, its own numbers are usually the most persuasive starting point. When that history is thin, distorted, or nonexistent, an outside benchmark may be the only credible path to a number.
I am Joey Friedman, a CPA, Accredited in Business Valuation (ABV), forensic accountant, and economic-damages expert witness based in Florida. Choosing between these two methods is one of the first decisions I make on any lost-profits engagement, and it is one of the decisions opposing counsel scrutinizes hardest. This article walks through what each method is, when each fits, the data each demands, where each tends to fail, and why I frequently run both. It is a focused look at method selection; for the full mechanics of building a damages model, see my broader piece on how to calculate lost profits.
What a But-For Projection Is Trying to Do
Every lost-profits claim rests on a counterfactual. The plaintiff is asking a court to award the profit it would have earned had the defendant not done whatever it did. That hypothetical world — the “but-for” world — does not exist on any tax return or bank statement. It has to be reconstructed.
The reconstruction always follows the same logic. I estimate the revenue the business would have generated absent the harm, subtract the costs it would have incurred to produce that revenue, and arrive at the profit it lost. Only the net figure is recoverable as damages; lost revenue by itself overstates the harm because the business never had to spend the money to earn it.
The hard part is the revenue side. Costs can often be derived from historical ratios once revenue is set, but the but-for revenue figure is where the methods diverge and where most of the courtroom fighting happens. Before-and-after and yardstick are the two dominant ways to build that figure, and each answers the same question — “what would sales have been?” — from a different evidentiary anchor.
The Before-and-After Method
This method uses the plaintiff against itself. The premise is straightforward: a company that was performing at a certain level before the harmful event, absent that event, would have continued performing at a similar level or along its established trajectory. I take the pre-harm record — revenue, margins, growth — and carry it forward across the loss period to model what should have happened. The gap between that modeled performance and what actually happened is the loss.
This method is intuitive, and juries grasp it quickly. It speaks in the plaintiff’s own historical language rather than in abstractions about strangers’ businesses. When a company has several years of reasonably steady results and the wrongful act produced a visible break in the pattern, the before-and-after approach is often the cleanest and most defensible choice available.
When the Before-and-After Method Fits
I lean toward before-and-after when a few conditions hold:
- The business has enough operating history to reveal a genuine pattern, not just a year or two of scattered figures.
- That history is representative — it reflects normal operations, not a fluke quarter or a one-time windfall.
- The trajectory before the harm is stable or trending in a way I can support with reasons, not just slope a trendline and hope.
- I can isolate the effect of the wrongful act from everything else happening to the business at the same time.
The method also earns its keep in a common real-world situation: when there is a “before” but no usable “after.” Plenty of injured businesses have not recovered by the time of trial, or never will. In those cases the post-harm period offers no clean baseline, but the pre-harm record still tells the court what the business was capable of producing.
Where the Before-and-After Method Breaks Down
The fatal weakness of this method is causation. Comparing profits before to profits after proves a decline; it does not prove the defendant caused the decline. Courts have excluded experts who simply lined up “before” averages against “during” averages without accounting for everything else that could explain the drop — a lost key customer, a new competitor, a recession, a change in the company’s own management.
So the real work in a before-and-after analysis is not the projection itself. It is ruling out the alternative explanations. If a plaintiff’s largest account walked out the door for reasons that have nothing to do with the lawsuit, and I project as though that revenue would have continued, the entire model collapses on cross-examination. Before I carry a historical trend forward, I have to understand why the historical results looked the way they did, and I have to address every non-defendant factor that touched the loss period.
A second weakness is growth. Pulling a flat line forward is easy; the dispute is almost always about the slope. A defendant will argue the business would have stalled regardless; a plaintiff will argue it was about to take off. Whatever growth assumption I use has to be grounded in something — the company’s own demonstrated capacity, the size of its market, contracts already in hand — not in optimism.
The Yardstick Method
The yardstick method looks outward instead of backward. Rather than asking what the plaintiff did before, it asks what comparable businesses did during the same period, and infers that the plaintiff would have tracked them but for the harm. The benchmark — the “yardstick” — supplies the but-for performance the plaintiff’s own records cannot.
The comparison can be drawn from several sources, depending on what is available and credible:
- A genuinely similar company — same line of business, comparable size, comparable market, operating in the same economic conditions.
- A sibling operation the same owner runs — a second store, branch, or territory that the wrongful act did not touch, which makes for an unusually clean comparison because the ownership, systems, and management are held constant.
- Industry or sector data — growth rates and operating metrics published by trade associations or market-research firms, used to model how the plaintiff would have moved with its industry.
- The defendant’s own results — particularly in trade-secret or trademark cases, where the defendant’s performance using what it took can illuminate what the plaintiff lost.
- Franchise comparables — results of similar franchised units, where the franchise model makes outlets more directly comparable than independent businesses would be.
When the Yardstick Method Fits
The yardstick method comes into its own precisely where before-and-after fails: when the plaintiff lacks a usable history of its own. A business that was driven under before it built a track record, or one with too little operating history to project from, has nothing to carry forward — but a well-chosen benchmark can still establish what it would have earned. The method requires that relevant comparable data actually exist and that a reliable, demonstrable relationship connect the plaintiff’s operations to the yardstick.
Where the Yardstick Method Breaks Down
The entire method lives or dies on comparability, and comparability is hard. Truly similar companies are difficult to find, and the differences that matter — size, geography, capital structure, customer base, product mix, market share — can quietly destroy the analogy. A benchmark that is bigger, more diversified, or operating in a different competitive landscape is not a yardstick; it is a distraction, and courts have said so plainly.
The most dangerous version of the problem is cherry-picking. An expert who builds a benchmark out of companies chosen because they produce a flattering number, rather than because they are genuinely comparable, has built an advocacy tool, not an analysis. I have seen damages opinions diminished or thrown out because the “comparables” were larger, more diversified businesses lumped into a composite that no honest reading would treat as a peer group. When I use a yardstick, I have to defend not only the benchmark I picked but the ones I rejected, and I usually have to make adjustments for the differences that remain.
A Related Third Approach: Sales Projections and Market Models
Method selection is not strictly binary. A third family of approaches deserves mention because it often supplements the first two.
The sales-projection approach relies on forecasts or budgets the company itself prepared — ideally in the ordinary course of business, for some purpose unrelated to the litigation. A budget management built to run the company, long before any dispute arose, can be powerful evidence of what the company expected. But I never take such a document at face value. I test it against historical results, against industry conditions, and against management’s own track record of forecasting accurately. A projection prepared after the litigation began, by either side, gets far more skepticism, because everyone involved has an obvious interest in the answer.
The market-share (or market-model) approach assumes the plaintiff would have held its share of a defined market but for the harm, and sizes the loss from there. It can be useful when a market has few competitors and the data are clean, but it is the least-used of these methods because it is so easy to overreach. The classic failure is an expert who assumes a tiny company would have grown to rival the market leaders, building a damages number on an assumption that is really just the conclusion dressed up — with no historical performance to support it. Courts have rejected exactly that reasoning.
How Courts and Daubert Frame Method Selection
None of these methods is “the right one” in the abstract. Under the reliability standards that govern expert testimony, what matters is whether the chosen method rests on sufficient facts, applies sound principles, and fits the specific facts of the case. A perfectly orthodox before-and-after analysis can be excluded if it ignores an obvious alternative cause; a yardstick analysis can be excluded if the comparables are not truly comparable. The method is only as good as the support underneath it.
This is why the reasonable certainty standard does so much work in damages disputes. Reasonable certainty does not demand mathematical precision — courts accept that a but-for world can never be measured exactly — but it does demand that every meaningful assumption be backed by the best available evidence. The standard applies across the whole damages period, not just the first year, which means a method that looks solid in year one can become speculative by year four if the growth assumptions outrun the support. Selecting a method is really selecting which evidentiary foundation I am prepared to defend, year by year, under oath.
Why I Often Run More Than One Method
When the data allow it, I prefer to calculate damages under more than one method and see whether the answers converge. This is not redundancy; it is a check on my own reasoning.
If a before-and-after projection and an independently constructed yardstick land in roughly the same range, each corroborates the other, and the combined opinion is far harder to dislodge. If they diverge sharply, that divergence is information — it tells me an assumption somewhere is doing too much work, and I would rather discover that at my desk than have opposing counsel discover it at deposition. Good forecasting means actively trying to prove your own number wrong before anyone else does. Cross-checking methods is one of the most effective ways to do that.
A Hypothetical Illustration
The following figures are entirely hypothetical. They are invented to show the mechanics of the two methods and do not come from any actual case or client.
Suppose a regional service firm was harmed by a former partner who breached a non-compete and pulled away clients. Before the breach, the firm’s revenue ran roughly as follows:
- Year 1: $4,000,000
- Year 2: $4,200,000
- Year 3: $4,410,000
That is a steady 5% annual growth pattern. Under the before-and-after method, I would project the same 5% trajectory forward into the loss period, producing but-for revenue of about $4,630,000 in Year 4 and about $4,862,000 in Year 5. If actual revenue collapsed to $3,500,000 and $3,800,000 in those years, the modeled revenue loss would be roughly $1,130,000 and $1,062,000, or about $2,192,000 before deducting the variable costs the firm avoided by not servicing that work.
Now suppose the firm’s own history were unreliable — say it had only been operating eighteen months. Under the yardstick method, I might turn to industry data showing comparable firms in the same market grew about 4% over the same span. I would apply that benchmark growth to whatever clean revenue base I could establish, then make adjustments for any way the subject firm differed from the benchmark group. The two methods would not produce identical numbers, and the difference between them would itself become something I would have to investigate and explain.
In a real engagement, I would then deduct only the incremental costs that disappeared along with the lost revenue, address every non-defendant factor that touched the loss period, and discount future losses to present value. The point of the illustration is narrower: the same underlying harm, viewed through two different methods, draws its but-for revenue from two entirely different sources of proof.
Common Errors That Sink a Method
Across both methods, the same handful of mistakes recur, and each one is an invitation for exclusion:
- Cherry-picked comparables or base periods. Choosing the benchmark companies or the historical years that flatter the client, rather than the ones that fairly represent the business, is the fastest way to lose credibility.
- An unrepresentative base period. Projecting forward from a window that included a one-time windfall, a lost anchor client, or an unusual contract produces a trend that never really existed.
- Ignoring confounding factors. Treating the defendant as the cause of a decline without ruling out the economy, competition, customer attrition, or the plaintiff’s own missteps.
- Unsupported growth assumptions. Carrying a steep growth rate into the future with nothing behind it — not market size, not capacity, not committed orders.
- Overreaching benchmarks. Comparing a small business to far larger or more diversified companies and pretending the differences do not matter.
Avoiding these is most of the discipline of the work. The arithmetic of a lost-profits model is rarely the hard part; the judgment about which method the facts will actually support, and which assumptions that method can carry, is the part that holds up in court.
FAQ
Which method is better, before-and-after or yardstick?
Neither is categorically better. The before-and-after method is usually stronger when the plaintiff has a stable, representative operating history; the yardstick method is usually necessary when that history is thin, distorted, or absent. The facts of the case dictate the choice, and a method that is wrong for the facts will not survive scrutiny no matter how carefully it is executed.
Can both methods be used in the same case?
Yes, and I often do when the data support it. Running an independent yardstick analysis alongside a before-and-after projection lets each method corroborate the other. Convergent results strengthen the opinion; divergent results flag an assumption that needs a closer look before trial.
Why is the yardstick method risky?
Because it depends entirely on the benchmark being genuinely comparable. Differences in size, geography, capital structure, customer base, or product mix can break the analogy, and courts routinely diminish or exclude yardstick opinions built on comparables that are not truly similar to the plaintiff.
What if the business is too new to have a track record?
A limited operating history pushes the analysis toward the yardstick method or toward credible pre-litigation projections, since there is little of the company’s own past to carry forward. New and early-stage businesses face a higher bar to prove their losses with reasonable certainty, and some jurisdictions apply special rules, so the legal landscape has to be checked alongside the financial analysis.
How do courts decide whether to accept a method?
Courts assess whether the method rests on sufficient facts, applies reliable principles, and fits the specific case — and whether the resulting opinion meets the reasonable certainty standard. A sound method poorly supported can be excluded just as readily as an unsound one, which is why the evidentiary foundation matters as much as the method label.
How can I discuss a potential lost-profits matter with you?
You can reach me directly at 954-282-9615 to talk through the facts of a matter and which approach the available evidence would support. I work with attorneys throughout Florida on damages quantification and related expert witness and litigation support, as part of a broader practice in economic damages.
About the Author
Joey Friedman is a CPA, Accredited in Business Valuation (ABV), and forensic accountant who holds a Master of Accounting and a Master of International Business and is a member of the AICPA and the Association of Certified Fraud Examiners. He also holds a Florida real estate license. Beyond those credentials, he has personally owned and operated more than a dozen of his own businesses across industries including marketing, printing, transportation, restaurants, hospitality and entertainment, and event planning — so when he selects between a before-and-after and a yardstick approach, he weighs it with both a financial expert’s rigor and an operator’s sense of how real businesses actually build and lose revenue.