II
Having found that both policies are to be considered “primary,” we are brought to the question of how should the liability be prorated where the total loss does not exceed the limits of either policy. American argues that the loss should be prorated according to the policy limits. Because Carriers provided $2,990,000 of coverage compared to only $250,000 for American, appellant contends that Carriers should bear close to ninety percent of the settlement cost. Carriers, on the other hand, argues that the loss should be shared equally between the insurers, the approach adopted by the presiding Justice.
There are three basic methods of proration. The majority rule, the one urged upon by appellant, prorates liability according to the limits contained in each policy.5 The next, which is seldom followed, prorates on the basis of the premiums paid to each insurer.6 Finally, there is a minority but growing number of courts which prorate the loss equally up to the limits of the lower policy,7 the approach adopted by the court below.
Each method is grounded on the premises, often unarticulated, that on equitable principles the loss should be shared among the insurers either on the basis of the risk that they have undertaken or the benefit they have received. In its clearest expression, the majority rule has been justified bn the theory that
the burden imposed on each insurer is generally proportional to the benefit which he received, since the size of the premium is most always directly related to the size of the policy. Lamb-Weston, Inc. v. Oregon Automobile Insurance Company, supra note 5 at 137, 346 P.2d at 647.
On precisely these grounds, the majority rule has been criticized since “[i]t is commonly known that the cost of liability insurance does not increase proportionately with the policy limits.” Cosmopolitan Mutual Insurance Company v. Continental Casualty Co., supra note 4 at 564, 147 A.2d at 534. Once minimum coverage has been obtained, significant supplemental coverage can be provided at only a modest increase in cost.
On the other hand, if the majority rule is less equitable than that minority approach which apportions on the basis of premiums received, it has the advantage of facile application. Unless the multiple policies cover the identical risks, there would be too many variables affecting the premiums to permit them to serve as a benchmark for an equitable adjustment. Nationwide Mutual Insurance Company v. State Farm Mutual Automobile Insurance Company, 209 F.Supp. 83 (N.D.W.Va.1962).
The minority rule adopted by the presiding Justice utilizes the best aspects of both approaches without the limitations. Like the majority rule, it is easy to administer. It would simply require each company to contribute equally until the limits of the smaller policy were exhausted, with any remaining portion of the loss then being paid from the larger policy up to its limits. Nationwide Mutual Insurance Company v. State Farm Mutual Automobile Insurance Company, supra; Dairyland Insurance Company v. Drum, 568 P.2d 459, 464 (Colo. 1977) (Carrigan, J., dissenting in part).
Unlike the majority rule, this Solomon-like approach comports with a most basic sense of justice. See Exodus, ch. 21, par. 35 (“When one man’s ox hurts another’s ox so badly that it dies, they shall sell the live ox and divide this money as well as the dead animal they shall divide equally between them.”) Moreover, the majority rule un
5
. See, e. g., State Farm Mut. Auto. Ins. Co. v. General Mut. Ins. Co., 282 Ala. 212, 210 So.2d 688 (1968); Buckeye Union Ins. Co. v. State Auto. Mut. Ins. Co., supra note 4; Lamb-Weston, Inc. v. Oregon Auto. Ins. Co., 219 Or. 110, 346 P.2d 643 (1959); Pacific Indem. Co. v. Federated Am. Ins. Co., 82 Wash.2d 412, 511 P.2d 56 (1973).
6
Insurance Co. of Tex. v. Employers Liab. Assur. Corp., supra.
7
See, e. g., Ruan Transport Corp. v. Truck Rentals, Inc., 278 F.Supp. 692 (D.Colo.1968); Ryder Truck Rental, Inc. v. Schapiro & Whitehouse, Inc., 259 Md. 354, 269 A.2d 826 (1970); Cosmopolitan Mut. Ins. Co. v. Continental Cas. Co., supra note 4.