There was a time when justices were keenly sensitive to keeping it short. Justice Lewis F. Powell Jr. wrote a memorandum to his law clerks in 1984 saying that “a frequent and justified criticism of this court is that opinions are too long” and “are overburdened with footnotes.” This can, he said, “leave lower courts and lawyers in doubt as to the law.”

These days, the writing emanating from the court can be bureaucratic and unmemorable.

“They just don’t make great movie lines the way they used to,” said Fred R. Shapiro, an associate librarian at Yale Law School and the editor of The Oxford Dictionary of American Legal Quotations. “They also don’t make great Supreme Court passages the way they used to.”

With the declining docket, justices have more time to hone their writing. But the available evidence suggests they rely on their clerks to produce first drafts, which the justices then edit.

“Although today’s Supreme Court opinions are no more poorly written on average than opinions from the era in which the justices wrote their own opinions, there is nonetheless a loss when opinions are ghostwritten,” Judge Richard A. Posner of the United States Court of Appeals for the Seventh Circuit wrote in The New Republic in 2006. “Most of the law clerks are very bright, but they are inexperienced; and judges fool themselves when they think that by careful editing they can make a judicial opinion their own.”

Delegating actual drafting to law clerks who are typically just two years out of law school, critics say, can be an abdication of judicial authority or at least an invitation to uneven and ambiguous prose.

A forthcoming study from two professors at the University of Toronto tried to identify the amount of ghostwriting on the court by developing software to analyze how justices’ writing styles varied from opinion to opinion and term to term.

“A justice who wrote her own opinions would presumptively possess a less variable writing style than a justice who relied heavily on her law clerks,” wrote Jeffrey S. Rosenthal and Albert H. Yoon, the authors of the study.