Wilk v. American Medical Association

Licensed chiropractors including Wilk (plaintiffs) sued the American Medical Association (defendant), claiming it conspired to boycott the chiropractic profession in violation of the Sherman Act; the district court agreed and issued an injunction against the boycott, and the AMA appealed. On an earlier appeal, the court had ruled that if Wilk showed the boycott restricted rather than promoted competition, the burden shifted to the AMA to prove (1) a genuine concern for scientific patient care, (2) that the concern was objectively reasonable, (3) that it was the dominant motivation for the boycott, and (4) that it could not have been adequately served by less restrictive means.

Whether a professional association's boycott of a specific profession constitutes an unreasonable restraint of trade under Sherman Act section 1's rule of reason when the association possesses significant market power.