What an economic expert does in litigation, the reliability and general-acceptance admissibility frameworks, what gets challenged in economic testimony, deposition versus trial, disclosure, and how to select an economist.
An expert witness is permitted to offer opinion testimony because the subject requires specialized knowledge that the trier of fact does not have. The governing frameworks generally require that the witness be qualified by knowledge, skill, experience, training, or education; that the testimony rest on sufficient facts or data; that it be the product of reliable principles and methods; and that those principles be reliably applied to the facts of the case. A forensic economist meets those requirements by building the damages calculation from the records and published data and by documenting every step.
The economist's function is to help the judge or jury understand what a loss is worth, not to decide the case. The economist does not opine on liability, on causation of the injury, or on medical or vocational questions, and a report that strays into those areas invites exclusion. What the economist does is translate the facts the record establishes and the opinions other experts supply into a projected loss and a present value, and explain the assumptions so the trier of fact can weigh them.
The economist's obligation runs to the accuracy of the method, not to the retaining party. The professional associations in the field publish ethics statements that call for the same method regardless of who retains the economist and for disclosure of the assumptions and their sources. An economist who advocates rather than analyzes is less credible, more vulnerable on cross-examination, and a liability to the case.
Whether an economist's opinion is admissible depends on the jurisdiction's framework. Federal courts and most state courts apply a reliability-based gatekeeping framework under which the trial judge decides whether the method is reliable and reliably applied, considering factors such as whether the method has been tested, whether it has been published and peer reviewed, its known or potential rate of error, the existence of controlling standards, and its general acceptance in the field. The factors are not exclusive, and the inquiry extends to technical and other specialized knowledge, including economics, not only to laboratory science.
A minority of states retain a general-acceptance framework, which asks whether the method is generally accepted in the relevant professional community and does not separately weigh testability or error rates. Under either framework the mainstream methods of forensic economics, projection from documented earnings, published worklife and life tables, replacement cost valuation of household services, and discounting at low-risk yields, are well accepted. The admissibility frameworks post compares the two in more detail, and counsel confirms the governing framework for the case against primary sources.
In economic testimony, challenges rarely attack the discipline. They attack inputs: an earnings base that ignores the tax returns, a growth rate inconsistent with the discount rate, a worklife horizon with no table behind it, post-event earnings that ignore a documented return to work, a consumption deduction omitted from a death claim, or a projection for a business with no history. Courts have excluded opinions where the gap between the data and the conclusion was too wide to bridge with the expert's say-so. A report built on stated sources with each input visible is positioned to survive that review.
Most expert testimony is given at deposition, not at trial. Opposing counsel examines the economist under oath on qualifications, the records reviewed, the method, each input and its source, and the opinions reached, and the transcript will be used at trial to impeach any departure. Preparation is the same as for trial: the economist should be able to defend every schedule in the report from memory, identify the source of every figure, and explain why each alternative the other side proposes was or was not adopted.
Retaining counsel should schedule a preparation session before the deposition to review the opinions, identify the inputs most likely to be contested, and confirm that the economist has everything produced since the report was written, including new pay records, updated medical opinions, and the opposing economist's report. A supplemental schedule prepared before the deposition is far better than a concession during it.
At trial the audience changes. The jury must understand the calculation and credit it. Direct examination walks through the records, the method, and the schedules in order, using the report's own tables as demonstratives. Cross-examination will press on the contested inputs and try to draw concessions that the number could be smaller. An economist who has presented the sensitivity of the result in the report, rather than a single figure, can agree that a different input gives a different result without conceding that the report is wrong.
In federal court a retained expert's written report must contain a complete statement of all opinions and the basis and reasons for them, the facts or data considered in forming them, any exhibits used to summarize or support them, the witness's qualifications and publications, a list of prior testimony for the preceding years, and a statement of compensation. Most state courts require a subset of these elements, sometimes through interrogatory answers rather than a report, and the timing is set by the scheduling order. The disclosure guide outlines the elements and the traps.
For the economist the practical points are three. First, the report should be complete: an opinion that is not in the report may be excluded at trial. Second, the facts or data considered include everything reviewed, not only what was relied upon, and the work file should be organized so it can be produced. Third, the duty to supplement continues, so new records that change an input call for a supplemental schedule rather than a surprise at deposition.
The prior testimony list is discoverable and will be read. An economist with a balanced history of plaintiff and defense work, and with a method that does not change between them, is more credible than one whose results always favor the retaining side. Published writings are also fair game, and an economist should not testify to a method the economist has criticized in print without explaining the difference.
Four questions identify the right economist for a damages case. First, training: graduate education in economics or a closely related field, and familiarity with the forensic economics literature and the published standards the associations in the field maintain. Second, testimony experience: depositions and trials in the relevant jurisdictions, for both plaintiff and defense, with a record that shows the method holding constant across engagements. Third, method: does the economist build from the records and published data, state every assumption, and show sensitivity, or deliver a single number with a narrative? Reviewing a redacted prior report answers this quickly.
Fourth, communication. The economist must be able to explain present value, worklife expectancy, and personal consumption to a jury in plain language and to hold that explanation under cross-examination. Reading a deposition transcript or watching prior trial testimony is the most reliable way to judge this before retention.
Timing matters as much as selection. An economist retained early can identify the records the calculation will need, coordinate with the medical and vocational witnesses on the assumptions the economic analysis will adopt, and inform discovery on the other side's damages theory. The when to retain guide describes the signals, and the team page describes the economists here.
That the economist is qualified by training and experience, that the opinion rests on sufficient facts or data, that it applies reliable methods, and that those methods were reliably applied to the case. For economic testimony the method is rarely the issue; the inputs are.
Because most expert testimony is given at deposition, and the transcript will be used at trial to impeach any departure from it. The economist should be able to defend every schedule from memory, identify the source of every figure, and have reviewed everything produced since the report was written.
In federal court and many state courts it may be excluded at trial. New records that change an input call for a supplemental schedule served under the duty to supplement, not a new opinion offered for the first time at deposition or trial.
By training in economics or a closely related field, testimony experience for both plaintiff and defense in the relevant jurisdictions, a method that builds from records and published data with stated assumptions and sensitivity, and the ability to explain present value and worklife expectancy to a jury in plain language.
Request a consultation on Expert Witness Testimony Guide or call (201) 343-0700. Plaintiff and defense counsel.