Tuolumne

Plaintiffs, County of Tuolumne (the “County”) and Dr. Eric Runte, a family practitioner, appeal the district court’s grant of summary judgment in favor of defendants on their claims of antitrust violations under Section 1 of the Sherman Act, 15 U.S.C. § 1 , for restraint of trade, conspiracy to boycott, and illegal tying. 1 *1152 The alleged restraint is a change in the cesarean-section (“C-section”) eredential-ing, or privileging, criteria for physicians by Sonora Community Hospital (“SCH”). The change essentially forecloses a class of medical service providers — family physicians — from the C-section service market.

For the reasons discussed below, we affirm the district court’s grant of summary judgment for defendants.

I. FACTUAL AND PROCEDURAL BACKGROUND

Sonora, California, has two hospitals, defendant SCH and Tuolumne General Hospital (“TGH”). SCH, a non-profit, private hospital, has the second highest C-section rate in the Adventist West Health Care System, of which it is a part. Dr. Christopher Mills and defendant obstetricians, Drs. Teel, Lawrence Brunei, and Louis Erich (“defendant OBs”), have privileges to perform C-sections at SCH. 2 They are all members of the SCH…