III. ERIE'S IMPLEMENTATION: RETHINKING DOCTRINAL PUZZLES
Parts I and II focused on Erie's functions; this Part focuses on its form. The morass of cases constituting Erie jurisprudence address several recurring problems that pose enduring puzzles. This Part illustrates how a more nuanced account of Erie's components can provide a new perspective on puzzles that have confounded courts and commentators for decades. For each puzzle, courts need to know whether their task is to create federal law, interpret federal law, prioritize conflicting laws, or adopt non-federal law. Courts likewise must recognize the difference between choosing an authoritative government, an authoritative institution within that government, and a rule that the institution would endorse.
The following sections analyze seven puzzles implicating all four of Erie's components. The goal is not to provide definitive answers, although I do offer some. Instead, the discussion exposes common themes underlying ostensibly dissimilar puzzles and places each puzzle in a context that helps to identify solutions.
First, analyzing multiple puzzles in the same article highlights how confusion in each area arises for similar reasons. This similarity is often difficult to discern because judicial opinions and scholarship usually address individual puzzles in isolation. Each problem might therefore appear to be difficult for idiosyncratic reasons. The analysis in this Part reveals that many puzzles arise from or become more difficult because of a shared pathology: a failure to parse Erie into its components. Each puzzle may raise some unique issues, but a more precise account of Erie's distinct components would place those issues in a context that can lead to better solutions.
Second, the analysis in this Part situates each puzzle within one of Erie's components and shows how that context can lead to doctrinal reform. A more precise account of where each puzzle fits within the broad Erie landscape helps determine what questions courts should ask and how to formulate coherent answers.
A. Creation and the Puzzle of General Law: When Can Federal Common Law Incorporate or Choose General Law Rules that Could Not Apply of Their Own Force?
Erie's central holding that "[t]here is no federal general common law" walks a semantic tightrope between the concepts of "federal common law" and "general common law." (128) Shaking the rope highlights how Erie failed to articulate a normative theory that could shape the role of general law in the federal system. The potential utility of such a theory is evident in debates about whether federal common law should apply in some diversity cases and about the status of customary international law in United States courts.
The Court in Erie could not reject "federal common law" because federal courts routinely apply such law in multiple contexts. Judges and scholars often do not agree on when to apply and how to craft federal common law. But there is a broad consensus that courts can create federal common law in at least some cases that need a federal solution, but for which the Constitution, legislative action, and executive action have not directly supplied an answer. (129) Examples include rules governing interstate and foreign relations, the federal government's proprietary interests, and admiralty. (130)
Likewise, the Court could not deny the existence of "general common law" because the Court itself had been diligently consulting such law since the Founding. Justice Brandeis doubted whether general law was a stable and legitimate source of judicial authority. (131) However, he could not deny general law's historical and contemporary salience as a source of ideas and guidance. (132) Indeed, on the same day the Court decided Erie, Justice Brandeis filed another majority opinion applying a "federal common law" rule of "equitable apportionment" for resolving interstate water disputes. …