It’s rare for a court to appoint its own expert in a class action. But Judge Gleeson of the Eastern District of New York is poised to do precisely that in order to help him decide whether to grant final approval to the $7.25 billion proposed class settlement of antitrust claims by retailers challenging Visa’s and MasterCard’s interchange fees. Some observers say that the proposed class settlement in the case—In re Payment Card Interchange Fee and Merchant Discount Antitrust Litigation, No. 1:05-md-01720—would be the largest class settlement of private antitrust claims in U.S. history.

In November, Judge Gleeson granted preliminary approval to the proposed settlement, which reportedly calls for $6.05 billion to be distributed to class members and for a $.12 billion reduction in future interchange fees. Several major retailers and trade associations are expected to object to final approval of the settlement, after having objected to preliminary approval.

Judge Gleeson recently asked the parties if they had any objection to having law professor Alan Sykes—a leading law-and-econ scholar—advise the court “with respect to any economic issues that may arise in connection with the forthcoming motion for final approval of the proposed settlement.”

The complexity and multi-billion-dollar stakes of this case may have motivated Judge Gleeson to seek guidance from an independent expert regarding whether the proposed class settlement should be approved under Federal Rule of Civil Procedure 23(e). We haven’t seen judges evaluating other class action settlements—which generally present less complicated issues than this settlement appears to raise—consider appointing their own experts to assess the settlement’s fairness.