What an Expert Endorsement Actually Certifies

Answer first: two requirements, and the second one is the demanding one

The Federal Trade Commission's Endorsement Guides devote a separate section to endorsements by experts, and it imposes two obligations that operate independently.

The first is about the person. Whenever an advertisement represents, expressly or by implication, that the endorser is an expert with respect to the endorsement message, then the endorser's qualifications must in fact give the endorser the expertise that the endorser is represented as possessing with respect to the endorsement.

The second is about the work. An expert may take into account factors outside their expertise, such as taste or price, but the endorsement must be supported by an actual exercise of the expertise that the expert is represented as possessing, in evaluating product features or characteristics relevant to an ordinary consumer's use of or experience with the product. And that evaluation must have included an examination or testing of the product at least as extensive as someone with the same degree of represented expertise would normally need to conduct in order to support the conclusions presented in the endorsement.

That second requirement is what makes a credential in an advertisement a factual claim rather than a decoration. It asserts not only that a qualified person spoke, but that a qualified person did the amount of work their own field would consider necessary before saying what they said.

The Guides describe themselves as administrative interpretations of laws enforced by the Commission, providing the basis for voluntary compliance; practices inconsistent with them may result in corrective action under Section 5 if the Commission has reason to believe the conduct falls within what the statute declares unlawful.

The expertise has to match the subject, and the definition is broader than a license

The Guides define an expert, for their own purposes, as an individual, group, or institution possessing, as a result of experience, study, or training, knowledge of a particular subject which is superior to what ordinary individuals generally acquire.

Note what that definition does not require. It does not require a license, a degree, or a professional title. Experience alone can produce it, and the Guides' examples confirm that. In one, the president of a commercial home cleaning service speaks about a cleanser; because cleaning services use cleansers extensively in the course of their business, the advertisement likely conveys that the president has knowledge superior to that of ordinary consumers, and the statement is treated as an expert endorsement.

But matching matters. The first example in the section is an engineer endorsing an automobile: describing the endorser as an engineer implies professional training and experience that make the endorser well acquainted with the design and performance of automobiles, and if the endorser's field is, for example, chemical engineering, the endorsement would be deceptive.

The health example is the closer parallel. An endorser of a hearing aid referred to simply as a doctor — the advertisement, the Guides say, likely implies expertise in the area of hearing, as would be the case for a medical doctor with substantial experience in audiology or a non-medical doctor with the relevant doctorate. A doctor without substantial experience in that area might be able to endorse the product only if the advertisement clearly and conspicuously discloses the nature and limits of the endorser's expertise.

That is the general shape of the rule. A general credential plus a specific subject implies specific expertise in that subject, and the two have to line up or the gap has to be disclosed.

The evidence the expert looked at is part of the claim

The Guides give an example that makes the evaluation requirement concrete in a health setting. A medical doctor states in an advertisement for a drug that the product will safely allow consumers to lower their cholesterol by a stated amount. If the materials the doctor reviewed were merely letters from satisfied consumers or the results of a rodent study, the endorsement would likely be deceptive, because those materials are not the type of scientific evidence that others with the represented degree of expertise would consider adequate to support that conclusion about the product's safety and efficacy. Under those circumstances, the Guides say, both the advertiser and the doctor would be liable.

A second example, in the Guides' general section, splits liability in a way worth reading carefully. A dermatologist who is a paid advisor to a company posts that a product is clinically proven to work, having received a write-up of the study in question that indicates flaws so serious they preclude any conclusions about efficacy. Given their medical expertise, the Guides say, the dermatologist should have recognized those flaws and is subject to liability, and the advertiser is also liable.

The second half of that example inverts it. Suppose the expert asked for the supporting evidence, the study shown had no apparent design or execution flaws, but the company withheld a larger and better-controlled unpublished study that failed to find any statistically significant improvement. The claim would be deceptive and the company would be liable, but because the endorser did not have reason to know the claim was deceptive, the expert would not be.

So the expert's obligation is calibrated to what a person with that expertise should have been able to see in what they were given. It is not strict liability, and it is not a free pass either.

Where an expert endorsement implies a comparison, the comparison has to have happened

The section carries a comparative rule that is easy to miss and does a great deal of work.

To the extent that the advertisement implies the endorsement was based upon a comparison to another product or other products, that comparison must have been included in the expert's evaluation. And as a result of that comparison, the expert must have concluded that, with respect to those features on which the endorser is represented to be an expert and which are relevant and available to an ordinary consumer, the endorsed product is at least equal overall to the competitors' products.

Then the rule goes one step further. Where the net impression created by the endorsement is that the advertised product is superior to other products with respect to any such feature, the expert must in fact have found such superiority.

The cleaning-service example shows how loosely a comparison can be implied. Because the advertisement implies the service has experience with a reasonable number of leading competing brands available to consumers, the service must in fact have that experience and must have determined, based on its expertise, that the endorsed product's cleaning ability is at least equal — or superior, if that is the net impression — to those competitors' products. But because nothing in that advertisement said the product was chosen or selected or evaluated side by side, it is sufficient that the service relied on accumulated experience rather than formal comparisons.

There is also a relevance limit, and its example is a health one. A manufacturer represents that a large metropolitan hospital selected its non-prescription drug product over competing products. The hospital chose it because each dose was packaged separately, a package form not generally available to the public. The Guides say the endorsement would be deceptive, because the basis for the choice — convenience of packaging — is neither relevant nor available to consumers, and the basis for the decision was not disclosed.

Doctors recommend, tests prove, and the level of proof the words import

The Commission's advertising substantiation policy statement approaches this from the advertiser's side, and it names the exact phrase.

Many advertisements, it says, contain express or implied statements regarding the amount of support the advertiser has for the product claim. When the substantiation claim is express — it gives tests prove, doctors recommend, and studies show as the examples — the Commission expects the firm to have at least the advertised level of substantiation.

It then closes the obvious workaround. An advertisement may imply more substantiation than it expressly claims, or may imply to consumers that the firm has a certain type of support; in such cases the advertiser must possess the amount and type of substantiation the advertisement actually communicates to consumers.

Where no level is named or implied and there is no other evidence of what consumers expect, the statement says the Commission assumes consumers expect a reasonable basis, and lists the factors that determine what that is: the type of claim, the product, the consequences of a false claim, the benefits of a truthful claim, the cost of developing substantiation, and the amount of substantiation experts in the field believe is reasonable.

One more rule from that statement matters here, because it defeats a common repair. The reasonable basis doctrine requires that firms have substantiation before disseminating a claim. The Commission may, in its discretion, consider material developed afterwards in three named circumstances, but it states that it will consider only post-claim substantiation that sheds light on pre-existing substantiation, and that advertisers will not be allowed to create entirely new substantiation simply because their prior substantiation was inadequate.

What a reader can check

The questions that follow from all of this are concrete, and they are mostly about specificity.

What exactly is the credential, and is it a credential in the subject the sentence is about — hearing, weight, metabolic medicine — or a general one being borrowed for a specific claim. The Guides treat the mismatch case as deceptive absent a clear disclosure of the nature and limits of the expertise.

Does the endorsement, read as a whole, imply a comparison. Words like chosen, selected, preferred over, or better than pull in the comparative requirement, and a superiority impression requires that the expert actually found superiority in the features they are represented as expert about.

Does a phrase in the advertisement name a level of proof. Clinically proven, tests prove, studies show and doctors recommend are express substantiation claims, and the substantiation policy statement says the firm is expected to have at least the advertised level.

And is the relevant thing available to an ordinary buyer. The hospital example turned on a basis for selection that consumers could not obtain and were not told about.

None of this establishes that any particular endorsement is deceptive. That is a determination for a regulator or a court on a specific record, and nothing here asserts or predicts one about any person or company.