The predominance requirement is a stumbling block in indirect purchaser actions. See Sugai Prods., Inc. v. Kona Kai Farms, Inc., No. 97-00043.SPK, 1997 WL 824022, at 13 (D. Haw. Nov. 19, 1997). In Wood v. Abbott Labs., Inc., plaintiff's request to certify a class of indirect purchasers of brand-name prescription drugs was denied. The court noted that the plaintiff's expert, who was the plaintiffs' expert in Karofsky, proposed theories that did not provide a method for calculating each class member's individual damages, as required by Michigan law. Wood v. Abbott Labs., Inc., No. 96-512561-CZ, 1997 WL 824019, at 2 (Mich. Cir. Ct. Sept. 11, 1997). In Kerr v. Abbott Labs., Inc., another indirect purchaser action in Minnesota, the court determined that individual issues would predominate because a showing of consumer impact would require an examination of myriad transactions at many levels of distribution to determine dates of purchase, prices, terms of any rebates, or discounts. The only common question was whether an antitrust violation occurred. Kerr v. Abbott Labs., Inc., No. 96-002837, 1997 WL 314419, at 2 (Minn. Dist. Ct. Feb. 19, 1997). In Holmes v. Abbott Labs., Inc., the court denied, without written comment, certification of the proposed class because questions of law or fact common to the class members did not predominate over questions affecting individual members. Holmes v. Abbott Labs., Inc., No. 94-744, at 1 (Mich. Cir. Ct. July 10, 1995). McCarter v. Abbot Labs., Inc. involved an unsuccessful effort to certify indirect purchasers of infant formula products under Alabama law. McCarter v. Abbott Labs., Inc., No CV 91-050, at 2 (Ala. Cir. Ct. April 9, 1993). The court concluded that the plaintiffs could not show proof of impact and noted that the evidence revealed very little correlation between wholesale and retail pricing. Id. at 7. In Keating v. Philip Morris, Inc., a proposed class of cigarette purchasers sued cigarette manufacturers for price fixing under state antitrust law. Keating v. Philip Morris, Inc., 417 N.W.2d 132, 134 (Minn. Ct. App. 1987). The class was not certified based on, among other things, the lack of any formula to calculate damages. Id. In Borden, Inc. v. Universal Indus. Corp., indirect purchasers of refined sugar were proposed as a class under Mississippi's antitrust laws. Borden, Inc. v. Universal Indus. Corp., 88 F.R.D. 708, 709 (N.D. Miss. 1981). The court concluded that "[d]etermination of damages would likely require years of proof regarding the effect of a conspiracy between Borden and other sugar companies on the various levels of distribution." Id. at 710; see also Pischenich v. Abbott Lab., Inc., No. MC 94-6868 (Minn. Dist. Ct. May 26, 1995) (class certification denied without comment).