The Supreme Court has issued an opinion in Biestek v. Berryhill, a Social Security case. Here's an excerpt from the Supreme Court's syllabus of its opinion:
... Biestek proposes a categorical rule that the testimony of a vocational expert who refuses a request for supporting data about job availability can never clear that bar. To assess that proposal, the Court begins with the parties’ common ground: Assuming no demand, a vocational expert’s testimony may count as substantial evidence even when unaccompanied by supporting data.
If that is true, is it not obvious why one additional fact—a refusal to a request for that data—should make an expert’s testimony categorically inadequate. In some cases, the refusal to disclose data, considered along with other shortcomings, will undercut an expert’s credibility and prevent a court from finding that “a reasonable mind”could accept the expert’s testimony. But in other cases, the refusal will have no such consequence. Similarly, the refusal will sometimes interfere with effective cross-examination, which a reviewing court may consider in deciding how much to credit an expert’s opinion. But other times, even without supporting data, an applicant will be able to probe the strength of the expert’s testimony on cross-examination.Ultimately, Biestek’s error lies in his pressing for a categorical rule, applying to every case in which a vocational expert refuses a request for underlying data. The inquiry, as is usually true in determining the substantiality of evidence, is case-by-case. It takes into account all features of the vocational expert’s testimony, as well as the rest of the administrative record, and defers to the presiding ALJ, who has seen the hearing up close.By the way, here's an excerpt from the dissent of Justice Gorsuch, joined by Justice Ginsburg:
... Veteran Social Security practitioners must be feeling a sense of déjà vu. Half a century ago, Judge Henry Friendly encountered Kerner v. Flemming, 283 F. 2d 916 (CA2 1960). There, the agency’s hearing examiner offered “nothing save [his own] speculation” to support his holding that the claimant “could in fact obtain substantial gainful employment.” Id., at 921. The Second Circuit firmly explained that this kind of conclusory claim is insufficient to meet the substantial evidence standard. In response,the Social Security Administration began hiring vocational experts, like the one in this case, to document the number of jobs available to a given claimant. But if the government can do what it did in this case, it’s hard to see what all the trouble was for. The agency might still rest decisions on a hunch—just so long as the hunch comes from an agency contractor rather than an agency examiner. ...Justice Sotomayor also dissented separately but mostly agreed with Justice Gorsuch. It sound odd for Gorsuch, Ginsburg and Sotomayor to be on the same side but Social Security cases don't fall easily into some simple liberal-conservative dichotomy.