In March, for instance, the court unanimously rejected an attempt by class-action lawyers in Arkansas to keep their case out of federal court by promising that their clients would accept less money than they might deserve. (The case had been filed in Miller County, Ark., where courts, according to business groups, are notorious for coercing large settlements from out-of-state defendants.)

But sometimes unanimity masks division. The most important business decision of the current term, Kiobel v. Royal Dutch Petroleum, severely limited human rights suits against corporations based on charges of complicity in abuses abroad. All nine justices agreed that the particular suit before them had to be dismissed, largely because every significant aspect of the case was foreign: the plaintiffs were Nigerian, the companies they sued were based in England and the Netherlands, and the atrocities the companies were said to have aided took place in Nigeria.

Yet the court split 5 to 4 along the usual lines about how far to leave the door open to similar suits. Chief Justice Roberts, writing for the majority, suggested that it would be the rare case indeed that was proper. Certainly, he said, it should not be enough that a multinational corporation does business in the United States. “Corporations are often present in many countries,” he wrote, “and it would reach too far to say that mere corporate presence suffices.”

Justice Breyer, in dissent, said such suits could play an important role in bringing to justice “torturers and perpetrators of genocide.”

THE Minnesota Law Review study did not rely on the common political science technique of coding each Supreme Court decision as conservative or liberal. To draw its main conclusions, it relied on a simpler formula, looking at cases with a business on one but not both sides. (The adversary might be an employee, job applicant, shareholder, union, environmental group or government agency.)

A vote for the business was counted as a pro-business vote.

By that standard, the study found, “the Roberts court is indeed highly pro-business — the conservatives extremely so and the liberals only moderately liberal.” Justices Ginsburg and Breyer, who spoke up in the Comcast case, were only slightly less likely to vote for business than the median justice in the survey but were in the bottom six for such votes in 5-to-4 decisions.

The arrival of Chief Justice Roberts in 2005 and Justice Alito in 2006 seem to have affected the behavior of the justices already on the court. The probability that the other three more conservative members of the court — Justices Scalia, Anthony M. Kennedy and Clarence Thomas — would vote for business grew to 56 percent from 52 percent. And the probability that Justices Ginsburg and Breyer would do so dropped to 32 percent from 38 percent.