In Re: Household International Tax Reduction Plan

POSNER, Circuit Judge.

An ERISA plan has asked us for permission to appeal from the district court’s decision to certify a suit against the plan as a class action. (For an earlier stage of our engagement with this protracted litigation, which produced three interlocutory appeals before class certification, see Mate v. Household International Tax Reduction Investment Plan, 388 F.3d 570 (7th Cir.2004).) Rule 23(f) of the civil rules gives us discretion to entertain such an appeal, but sets forth no criteria to guide the exercise of that discretion. We have devised our own criteria. The only one…