The number is the least informative thing in the report. The assumptions underneath it are where the case is.
Start a conversation with Cournot, the Institute’s damages concierge, already scoped to critiquing an opposing model. Pick a starting point, or describe the dispute directly.
A damages report arrives and the instinct is to read the conclusion. That is the least useful part of the document. The conclusion is an output of a chain — a measure chosen, a counterfactual constructed, inputs selected, costs treated one way rather than another, a period assumed, a rate applied — and each link is a place where a different reasonable choice produces a materially different figure. Reading a report properly means reconstructing that chain and identifying which link carries the most weight, because attacking the wrong one wastes the deposition. This is also the work that most reliably reveals whether you need your own expert, what kind, and how quickly.
Roughly the sequence a rebuttal expert works through on first reading.
Which framework and why. Sometimes the whole report answers a different question than the claim poses.
What world is assumed absent the conduct, and what evidence supports that world.
Where each material number came from, and whether the source bears the weight.
Which costs were deducted and on what basis. A frequent and productive line of attack.
Discounting, growth, and the length of the damages window. Small changes, large effects.
Which assumptions the report never subjects to a sensitivity analysis.
How the Institute approaches a rebuttal read.
Whether you challenge, rebut, or reprice the case.
Every long report contains small errors. The question is which ones move the number. Ranking the attacks by their effect on the conclusion is the difference between a damaging cross and a pedantic one.
At the counterfactual, because it usually carries more of the number than anything else and is the least constrained by evidence. Ask what world the expert assumes would have existed absent the conduct, and then ask what in the record supports it. Growth rates that exceed anything the business ever achieved, market share assumptions with no basis, or an assumed indefinite continuation of a favourable trend are all common and all attackable. After that, look at cost treatment, which is more technical, less intuitive to a jury, and frequently where the largest correctable error sits.
To testify, almost always. To decide what to do, not necessarily at first. Much of the initial read — identifying the measure, tracing assumptions, spotting where sensitivity was never tested — can be done by counsel with a structured approach, and that work sharpens the brief you give an expert later. What you cannot do without one is offer an admissible competing opinion or credibly assert that a method is unsound in the field. The efficient sequence is to understand the report well enough to know what kind of expert you need, then retain that person rather than a generalist.
Attacking the method aims at exclusion; attacking the inputs aims at the number. They are different objectives with different audiences. A methodological attack argues the approach is unreliable or does not fit the case, and it is the argument that supports a motion. An input attack accepts the framework and shows the figures fed into it are wrong or unsupported, which is often more persuasive to a jury because it does not require them to evaluate competing economic theory. Many cases run both, but knowing which is the primary theory shapes the deposition entirely.
It matters less than firms fear, and the anxiety is worth examining rather than indulging. A rebuttal is a narrower task than an affirmative damages case: it requires reading a model critically and explaining what is wrong with it, which is squarely academic work. What institutional scale genuinely buys is throughput — the ability to re-run analyses overnight, produce exhibits at volume, and absorb a heavy discovery and trial-support load. If the matter is data-intensive or the schedule is compressed, that capacity is a real consideration. If the fight is conceptual, an excellent individual economist is frequently the stronger rebuttal witness.
Describe the opinion you have received. The Institute will help you rank the attacks.