In the case of Northwest Wholesale Stationers, Inc. v. Pacific Stationery & Printing Co., 1984, the U.S. Supreme Court ruled that not all expulsions from cooperative purchasing organizations necessarily have significant anti-competitive effects that would classify them as per se violations of Section 1 of the Sherman Act (which prohibits business activities that reduce competition or create monopoly). The court held this view because such cooperatives often allow small companies to compete more effectively with larger ones by achieving economies of scale in both purchasing and warehousing merchandise. In this particular case, Pacific Stationery was expelled from a wholesale cooperative for failing to meet its purchase quota requirements and subsequently sued alleging antitrust violation. However, since there were no specific allegations indicating an intent to monopolize or control prices on part of Northwest Wholesale Stationers' expulsion decision, it was concluded that their actions did not constitute a per se violation.

In the dissenting opinion for Northwest Wholesale Stationers, Inc. v. Pacific Stationery & Printing Co., Justice White argued that the majority's decision to apply a per se rule of reason analysis was incorrect and inconsistent with previous antitrust case law. He contended that expulsion from a cooperative purchasing association could be considered an exclusionary practice under certain circumstances, which would warrant more stringent scrutiny than provided by the rule of reason approach adopted by the majority. Furthermore, he disagreed with the majority's view that such expulsions do not have significant anti-competitive effects unless they deprive competitors access to all reasonable supply sources or customers; instead, he believed any restriction on market participation should be viewed as potentially harmful competition-wise.