In the past few years, the legal academy has become more concerned with the question of how exactly a defendant's due process rights play out in the class action context.

Last year, DePaul Professor Mark Moller (whose pedigree does not suggest an immediate kinship with plaintiffs' attorneys) asked whether the due process arguments defendants invoke were really grounded in constitutional case law

Recently, Baylor Professor Jill Wieber Lens approached the issue from a different perspective: whether a defendant's insistence on due process in class action practice can be justified--as a policy matter--by either cost or accuracy. Her answer, in her paper No Matter the Enormous Cost: A Defendant’s Accuracy‐Based Right to Present Defenses, is no:

If the Court is willing to ignore the costs in cases like Dukes and Philip Morris—where the costs are enormous—then the costs of providing an additional procedural protection for defendants are likely never to be relevant. Thus, the only question will be whether the procedure will improve accuracy; if the procedure increases accuracy, perhaps even infinitesimally, the defendant has a right to it. A right based on the desire for perfect accuracy is questionable given that this accuracy is not realistic. It is even more questionable given the non‐consideration of the costs that accompany the procedures.

It's not entirely clear what Professor Wieber means by "costs" here: she seems to mean that the Supreme Court has not considered the cost to the plaintiff of gathering the evidence necessary to justify certifying a class (or punitive damages, in the Philip Morris case).

A class action is designed to reduce the costs of litigating large cases where it can do so consistent with due process. That means that class actions work best when the cost of complying with due process is relatively low. If a defendant insists on its right to challenge liability against each class member, and that challenge would require the same proof and reach the same result in each case, then a class is certifiable. (That's the commonality requirement in a nutshell.) Arguing that this requirement is too expensive is essentially arguing that less cohesive classes should get certified.

There's an obvious argument to be made about why that would be unfair to defendants. But most corporate defendants understand that rhetorically, people will sympathize with David over Goliath.

So let's talk instead about why this is a problem for David (in this case, other class members). Because it most assuredly is. A less-cohesive class that loses on the merits has sacrificed the claims of class members who were not like the named plaintiff--possibly because they had meritorious claims. A less cohesive class that wins on the merits will overcompensate the less-deserving class members at the expense of the more-deserving class members. (The attorneys will get their usual 30% cut.) Neither of these outcomes is good for the class as a whole. Accuracy is just as important for absent class members, as it is for defendants. The party with the least incentive to insist on accuracy remains class counsel, because counsel's fees are not linked to an accurate outcome.

Which all goes to reinforce a common (but counter-intuitive) point: in class actions, the interests of the absent class members and the defendants can often coincide in unexpected ways.