Barry and Hassler, two California physicians, appeal from a summary judgment entered in favor of Blue Cross of California (Blue Cross). Their complaint alleges that Blue Cross participated in price-fixing and a group boycott in violation of federal antitrust law. We have jurisdiction pursuant to 28 U.S.C. § 1291, and we affirm.
I
Blue Cross, a nonprofit corporation, offers various forms of medical insurance to residents of California. By statute, at least two-thirds of the members of the Blue Cross governing board must be duly appointed representatives of the public, so that no more than one-third of the board’s members can be physicians or representatives of hospitals with which Blue Cross has service contracts. Cal.Ins.Code § 11498 (West Supp.1986). In 1982, California enacted legislation authorizing private insurers to contract with hospitals and health care professionals to provide services for insureds at predetermined prices. Cal.Ins.Code § 10133 (West 1972 & Supp. 1986). Blue Cross decided to make such coverage available through an insurance package known as the Prudent Buyer Plan (the Plan).
Blue Cross contracted with physicians and hospitals to provide services at a fixed rate to those who subscribe to the Plan. If a subscriber receives treatment from one of these participating physicians, then Blue Cross pays for ninety percent of the cost of the service, once deductibles are satisfied. If a subscriber elects to use the services of a nonparticipating physician, Blue Cross pays only sixty to seventy percent of the physician’s customary fee. Both subscribers and participating physicians are free to deal with any other patient, physician, or insurance company. A participating physician, however, cannot refer a patient insured under the Plan to a nonparticipating *868 physician without the consent of the patient.
Hassler contracted to provide services under the Plan; Barry declined to do so. Barry and Hassler (the two doctors) filed suit in the district court claiming that the Plan resulted in price-fixing and a group boycott in violation of the Sherman Antitrust Act of 1890, 15 U.S.C. (Sherman Act), section 1, and that Blue Cross is a monopolist in violation of Sherman Act, section 2. They also asserted various state law claims. After several months of discovery, the district court granted Blue Cross’s motion for summary judgment on all federal claims and dismissed the pendent state law claims.
We review de novo whether the district court properly granted summary judgment.
Lojek v. Thomas,
II
The two doctors allege that the Plan represents a horizontal agreement among competing physicians. If so, the Plan is per se unlawful under section 1 of the Sherman Act because the Plan fixed prices for physician’s services.
See Arizona v. Maricopa County Medical Society,
A.
In
Maricopa,
physicians formed an organization to set maximum prices for physician services in Maricopa County, Arizona.
First, the two doctors point to evidence that Blue Cross obtained advice on the Plan from various physician groups. The record indicates that Blue Cross wanted to test the reaction of physicians before putting the Plan into final form. Blue Cross solicited comments from several physician groups on a draft of the proposed agreement for participating physicians. The record contains two letters that Blue Cross received from the California Radiological Society expressing some complaints that radiologists had about the Plan. Blue Cross received both letters in July 1983, the same month that it began contracting with participating physicians. Thus, the letters conceivably could have influenced Blue Cross. The record also contains a letter from a physician dated December 1983, after the Plan was already in effect, expressing his opinions about the Plan. The record does not indicate that Blue Cross made any changes in the Plan as a result of this or any other information received from physicians. We conclude that this evidence does not permit an inference of physician control of Blue Cross or of the Plan.
Cf. Maricopa,
The two doctors also argue that physician control sufficient to invoke Maricopa can be inferred from the existence of a “Physicians Relations Committee” that re *869 viewed both the plan and the fee schedules. The record contains a list of Blue Cross’s “Advisory Boards, Committees, and Senior Staff” for 1984. This list indicates that the Physician Relations Committee consisted of sixteen doctors. The list includes several other advisory committees — including a consumer relations committee and a hospital relations committee — whose membership totaled sixty-one, none of whom were doctors. The list also indicates that the Blue Cross Northern California Board of Directors had nineteen members including four doctors, and that the Southern California Board had nineteen members, of whom only two were medical doctors and one was a doctor of public health. Finally, the list names the eleven senior executives for Blue Cross in 1984, none of whom was a doctor.
The record shows that Blue Cross asked the Physician Relations Committee to review the Plan and to offer “comments and suggestions” before the Plan was implemented in 1983. The record also indicates that the committee reviewed certain proposed fee increases in 1984. No evidence was presented that either review had any effect on the Plan. Furthermore, nothing in the record suggests that the committee had final authority over any aspect of the Plan. Indeed, the only direct evidence relevant to this issue, the declaration of a Blue Cross vice president, states unequivocally that all decisions regarding the Plan’s terms and structure were made by Blue Cross’s staff, not by physicians.
Although the physicians of California could have secretly agreed first to set prices and then to enforce them through Blue Cross’s Physician Relations Committee, the two doctors have produced no evidence of such an agreement.
B.
The other claimed theory of horizontal agreement involves the doctrine of conscious parallelism. Under that doctrine, a tacit agreement is shown if
[1] knowing that concerted action was contemplated and invited, the [physicians] gave their adherence to the scheme and participated in it. [2] Each [physician] was advised that the others were asked to participate; [and 3] each knew that cooperation was essential to successful operation of the plan.
Interstate Circuit, Inc. v. United States,
Conspiracy cannot be inferred from this evidence, however, because the last element of the Interstate Circuit test is not present. The two doctors have not shown that the physicians were economically interdependent — that “cooperation was essential to successful operation of the plan.” Id. A showing of interdependence “is a necessary condition for inferring any conspiracy from parallelism.” VI P. Areeda, Antitrust Law 111411, 71 (1986). Without interdependence, “each actor is indifferent to the others’ behavior.” Id. at 70.
The most precise test for economic interdependence involves an economic analysis of an industry’s market structure. Economic interdependence exists only if an industry has relatively few competitors so that the actions of each has some impact on market price and thus on the conduct of competitors. Id. II 1429a, 175. The two doctors have offered no evidence to show that such an oligopolistic market structure existed among physicians. Indeed, the record indicates that more than 20,000 physicians practiced in Los Angeles county alone. With such numbers, individual physicians could not possibly have had enough market power to influence the behavior of their rivals.
Although less precise than the examination of market structure method, we can also evaluate interdependence in a commonsense fashion by examining the relationship between alleged conspirators. We do so by asking several questions, all of which *870 have interdependence as their focus. See id. ¶¶ 1411-15 at 69-93.
First, we determine whether each of the physicians had an independent business reason for his conduct.
See Fine v. Barry and Enright Productions,
Second, we ask whether joining the Plan required a commitment contrary to the physicians’ economic self-interest.
See Zoslaw v. MCA Distributing Corp.,
Finally, we determine whether an alleged conspirator would have benefited from having other physicians join the alleged conspiracy.
See First National Bank of Arizona v. Cities Service Co.,
Although other questions might also be asked, these are sufficient to dispose of this issue. Because the two doctors have not produced evidence that the physicians are interdependent, we cannot infer a tacit agreement.
Because the two doctors have not produced sufficient evidence of a horizontal agreement under any theory, summary judgment was proper on that issue.
See Brillhart v. Mutual Medical Insurance, Inc.,
Ill
The two doctors also allege a vertical conspiracy — between Blue Cross at one level and the physicians at another — to engage in unlawful restraints of trade. The two doctors argue that Blue Cross’s conduct here is controlled by
United States v. Colgate & Co.,
We begin our analysis by determining whether the participating physician agreements fall into a class of activity that
*871
has been condemned as per se unreasonable, or whether we should instead analyze them under the rule of reason.
Compare, e.g., Northern Pacific Railway Co. v. United States,
The two doctors argue, however, that if we do apply the rule of reason instead of per se analysis, summary judgment is necessarily precluded. They contend that under the rule of reason test a court must undertake an elaborate examination of the practice in question, balance its procompeti-tive and anticompetitive effects, and determine whether a less restrictive alternative is available. Such an examination, they assert, ordinarily can take place only after a trial and extensive fact finding.
See Poller v. Columbia Broadcasting System, Inc.,
Not every practice, however, need be subjected to such an elaborate analysis. “The language [of
Poller
] merely teaches caution.”
Barnes v. Arden Mayfair, Inc.,
First we consider whether the agreements have impermissible anticompetitive effects. The two doctors argue that the Plan has the consequence of boycotting or shutting out nonparticipating physicians by interfering with their access to patients insured by the Plan. We agree. However, every contract between a buyer and seller has precisely the effect of which the two doctors complain. When a buyer contracts with one seller, a second seller no longer has access to the buyer’s business to the extent it is covered by the existing contract. This consequence, however, is not unlawful.
See Colgate,
For a contract to have an impermissible anticompetitive effect, it must contain a provision that distorts transactions in an *872 other market. For example, we condemn tying arrangements where a seller offers a product only on condition that a buyer purchase a second product as well, because the contract distorts the market for the second product. Similarly, we may condemn distributional restraints that affect a buyer’s freedom to sell a product to a third party, or boycott agreements that affect a party’s freedom to deal with a third party.
The two doctors claim that just such market distortion arises from the referral clause in Blue Cross’s agreements with participating physicians. Under this clause, each physician “agree[d] to refer [patients insured by the Plan] to other [participating physicians] unless otherwise determined by [the referring physician] and agreed to by the [patient].” The clause does not deny a physician the right to refer patients to any person he chooses, whether participant in the Plan or nonparticipant. It does require physicians to notify patients if a referral is made to a nonparticipating physician.
The mere act of providing the information itself, as required under the referral clause, cannot be a cause of market distortion. The notification procedure is procom-petitive rather than anticompetitive. One of the foundations of an ideal competitive market is the free flow of information to buyers and sellers. Without notification, a patient would not know that a referral physician did not participate in the Plan and hence that this physician’s services were not covered as well. Notification under the referral clause, therefore, prevents “market failure” due to ignorance rather than causing market distortion.
However, the two doctors argue that we should consider the effect of this referral clause in light of the reduced benefits Blue Cross provides for treatment by a nonparticipating physician. Because of these reduced benefits, few patients will consent to treatment by a nonparticipating physician. Thus, the two doctors argue, the referral clause in effect implements a “refusal to deal.”
We agree that paying lower benefits for treatment by nonparticipating physicians greatly discourages patients from using such physicians. This, however, is simply the ordinary consequence of every commercial contract, as previously pointed out. When a consumer contracts to buy services from one health plan, the consumer will then have little or no demand for the services of a nonparticipating physician, especially if the consumer would have to pay more for these services. The contract does not mean that the parties have agreed to an unlawful concerted refusal to deal. Under the Plan, a consumer still enjoys complete freedom to seek treatment from a nonparticipating physician; moreover, a Plan physician can refer any or all of his patients to a nonparticipating physician. Ordinary competitive market forces — lower prices — have simply reduced the demand for the nonparticipating physician’s services. Nor does the system of reduced benefits for treatment by nonparticipating physicians represent an unlawful tying arrangement. The Plan does not require that the consumer purchase the services of any participating physician.
Therefore, although the vertical agreements in this case tend to foreclose nonparticipating physicians from doing business with patients insured under the Plan, the agreements do not cause impermissible market distortions. They do not prevent patients from seeing nonparticipating physicians, nor physicians from seeing nonsub-scribing patients. Neither do they prevent participating physicians from referring patients to nonparticipating physicians, nor from contracting with other insurance companies. Therefore, the agreements do not have any prohibited anticompetitive effects.
On the other hand, the vertical agreements between Blue Cross and the physicians do have certain procompetitive consequences. By demanding lower prices from participating physicians, Blue Cross injects an element of competition into the market for physician services that otherwise might not be present. The Plan also requires *873 that physicians agree to utilization review — oversight by Blue Cross to see that physicians provide the proper kind and level of care. It therefore offers consumers the added choice of health care services subject to a sort of central “quality control.” Blue Cross can only provide assured access to lower cost physicians and utilization review if it has physicians under contract. Therefore, the Plan, with its required vertical agreements with physicians, results in these added elements of competition.
Finally, the two doctors argue that a less restrictive alternative is available to Blue Cross. They suggest that, at the very least, Blue Cross should agree to reimburse policyholders for the services of nonparticipating physicians at the same rate as for participating physicians. But if Blue Cross did this, physicians would have a limited incentive to participate in the Plan because they would have access to Blue Cross subscribers without entering into an agreement. Such physician participation, however, is an essential element of the Plan. Therefore, the suggested less restrictive alternative is really no alternative at all.
Our conclusion here is supported by a number of decisions in which courts have reviewed and upheld health service plans similar to the one before us. In
Klamath-Lake,
The agreement that the Fourth Circuit found unlawful in
Virginia Academy of Clinical Psychologists v. Blue Shield of Virginia,
*874 IV
The final claim of the two doctors is that Blue Cross has monopolized the market for medical insurance in violation of Sherman Act section 2. To prevail on this claim, they must establish that Blue Cross has a sufficiently large share of a relevant market.
See Transamerica Computer Co. v. International Business Machines Corp.,
V
Because the two doctors have not produced sufficient evidence of horizontal conspiracy, because the vertical agreements between Blue Cross and the participating physicians do not unreasonably restrain trade, and because they have produced insufficient evidence of monopoly power, we affirm the district court’s judgment in favor of Blue Cross.
AFFIRMED.
