In several instances, third-party payers negotiate prices of health care services with providers. We show that a third-party payer may prefer to deal with a professional association than with the sub-set constituted by the more efficient providers, and then apply the same price to all providers....

One of the mechanisms that is implemented in the cost containment wave in the health-care sectors in western countries is the definition, by the third-party payer, of a set of preferred providers. The insured patients have different access rules to such providers when ill. The rules specify the...