Percolation's Value.

• Author: Coenen, Michael

Table of Contents Introduction I. The Practice of Percolation A. The History of Percolation B. Percolation Today 1. The Supreme Court's certiorari practice 2. Nationwide injunctions 3. Nationwide class certification 4. Nonmutual collateral estoppel 5. Multidistrict litigation 6. Patent litigation C. The Costs of Percolation II. Percolation's Informational Value A. Crowdsourcing B. Factual Debiasing C. Experimentation D. Audience Reactions E. Signaling III. Percolation's Institutional Value A. Percolation and Engagement B. Percolation and Lower Courts' Decisionmaking Capabilities C. Percolation and Supreme Court Nondecision D. Percolation and Reciprocal Legitimation IV. Percolation's Future A. Issue-Specific Evaluation B. Transparency C. Percolation Without the Costs? Conclusion Introduction

Few legal metaphors enjoy more prominence than that of a legal issue "percolating" through the courts. The underlying image is intuitive and appealing: Like crude and granular liquid seeping through a purifying filter, a difficult legal issue becomes clearer, cleaner, and more refined as more lower courts have the chance to weigh in on its merits. When at last the time comes for the Supreme Court to resolve that question for itself, the prior percolation of the issue will help the Justices render a decision that is especially thoughtful and well-informed. The process has its costs, to be sure: Issue percolation can yield delay, repetitive litigation, nonuniformity, and prolonged uncertainty about the content of the law. But proponents of the process maintain that those costs are often outweighed by the benefits that percolation provides. Percolation, the argument goes, has value. And the federal courts would do well to take its value into account.

This is by no means a merely academic idea. Much to the contrary, the Supreme Court and its individual Justices have adverted to percolation's value in decisions about matters of federal court practice and procedure. Just two Terms ago, in Box v. Planned Parenthood of Indiana & Kentucky, Inc., for instance, the Court justified its decision not to address one of the questions presented by pointing to its "ordinary practice of denying petitions insofar as they raise legal issues that have not been considered by additional Courts of Appeals," (1) with Justice Clarence Thomas stating more explicitly that "further percolation may assist our review of this issue of first impression." (2) Similarly, in Maslenjak v. United States, decided in 2017, Justice Neil Gorsuch noted in his separate opinion that "the experience of ... thoughtful colleagues on the district and circuit benches" can aid the Court by "yield[ing] insights (or reveal[ing] pitfalls)." (3) In Trump v. Hawaii, Justice Thomas wrote separately to express his concern that nationwide injunctions were "preventing legal questions from percolating through the federal courts," (4) and more recently, in Department of Homeland Security v. New York, Justice Gorsuch similarly worried that such injunctions undermined "the airing of competing views that aids this Court's own decisionmaking process." (5) And Justice Ruth Bader Ginsburg once maintained that "periods of 'percolation' in, and diverse opinions from, state and federal appellate courts may yield a better informed and more enduring final pronouncement by this Court." (6)

At the same time, and as other judges and commentators have maintained, percolation's value is neither obvious nor uncontested. Writing in 1986, then--Associate Justice William Rehnquist argued that percolation "makes very little sense in the legal world in which we live." (7) Three years earlier, Justice Thurgood Marshall had similarly questioned "those of my colleagues who agree with me [on the merits] but believe that this Court should postpone consideration of the issue until more State Supreme Courts and federal circuits have experimented with substantive and procedural solutions to the problem." (8) Scholars too have questioned whether "meaningful percolation occurs" when the Court waits for intercircuit conflicts before granting petitions for certiorari. (9) And they question whether, if percolation does occur, it really confers the concrete benefits that are often attributed to it. (10) The question of percolation's value, one might say, has itself been percolating for quite some time.

It is against this backdrop that we offer our own account of percolation's value--an account that offers several contributions to the existing literature. Our overall take is a qualifiedly skeptical one. Without discounting the possibility that some instances of percolation might confer benefits that exceed their costs, we are not convinced that, as a general matter, the Supreme Court should go out of its way to ensure that multiple lower courts offer answers to legal questions that the Court already intends to decide. (11) Thus, for instance, we reject the idea that the need to foster percolation generally provides a good reason for denying certiorari on (or otherwise declining to decide) an issue that the Court would otherwise be inclined to take on. Nor do we think that the potential effects on the percolation process should weigh as a significant factor in ongoing debates concerning nationwide injunctive relief, (12) nationwide class certification, (13) multidistrict litigation, (14) and other procedural questions that implicate the ability of multiple lower courts to opine on legal questions prior to Supreme Court review. (15) At best, we think, percolation's benefits will outweigh its costs under limited and contingent conditions--conditions not likely to replicate themselves across a broad range of cases.

We begin our analysis by tracing the history of the percolation metaphor itself--a history that, as best we can tell, existing legal scholarship has not yet set forth in any detail. We show in Part I that courts' and commentators' own interest in percolation's value is a relative latecomer to the jurisprudential scene. Indeed, for several decades after 1891, when Congress authorized the Court to exercise certiorari jurisdiction over decisions of the federal courts of appeals, conventional wisdom emphasized the values of comity and uniformity as primary desiderata of lower-court decisionmaking (16)--values in stark tension with the independent, conflict-generating style of decisionmaking on which effective percolation depends. (17) Having considered that history, we then turn to the present day, highlighting the various ways in which the question of percolation's value continues to carry practical relevance, not just in the most evident sense of guiding the Court's own certiorari practice but also in the subtler sense of informing debates about procedure and remedies across all levels of the federal court hierarchy.

With the stakes of the question on the table, we then catalog and consider a variety of different arguments that might be made in percolation's favor. We begin in Part II with the standard and oft-stated suggestion that percolation enhances Supreme Court decisionmaking by conferring informational value. (18) In particular, we outline five different ways in which percolation might generate useful information for the Court to consider when taking on a question for itself. Several of these informational accounts, we argue, founder not so much on the idea that percolation may produce information of value to the Court, but rather on the idea that percolation is uniquely capable of doing so. Much to the contrary, many of the ideas, insights, facts, and signals to which percolation might give rise are the same ideas, insights, facts, and signals that the Court would in any event confront when perusing the litigants' submissions, amicus briefs, and outside commentary that a decision to grant certiorari on the issue is likely to generate on its own. This rebuttal, to be sure, does not apply to the entirety of the informational case, and we do acknowledge that percolation might sometimes manage to yield information that the Court would otherwise have trouble obtaining. But it highlights an important defect in the conventional account of percolation's value, one that seems particularly glaring within our current informational age.

Having considered and largely rejected these informational arguments, we then ask in Part III whether percolation might have value wholly apart from its oft-presumed ability to improve the Court's resolution of particular legal questions. In particular, we consider four different institutional accounts that see the percolation process as beneficial to effective functioning of the federal court system as a whole. First, we consider the suggestion that percolation might help to create more occasions for the Court to engage directly with the work of the lower courts, thus facilitating a healthy and comity-enhancing intrabranch dialogue between the Court and its subordinates. (19) Second, we consider the possibility that percolation might help to improve the lower courts' own decisionmaking capabilities by ensuring that they have access to the sorts of difficult and high-profile cases that are most likely to sharpen their adjudicative skills. (20) Third, we consider the possibility that the Justices' own belief in percolation's value might help to incentivize the Court to maintain a beneficial noninterventionist posture toward issues that the lower courts can and should resolve themselves. (21) And finally, building on the recent work of Neil Siegel, (22) we consider the complex ways in which percolation might help to legitimate a controversial and politically sensitive Supreme Court decision, particularly under circumstances in which the Court can point to widespread lower-court consensus as indicative of that decision's legal validity. (23) These institutional rationales, we conclude, all carry some surface-level appeal. But, like their informational counterparts, they are...