37 Opinion of the Court. generally rests on one who claims its benefits," requires that respondent undertake this proof under the proviso of § 2 (a). Secondly, § 2 (b) of the Act specifically imposes the burden of showing justification upon one who is shown. to have discriminated in prices. And the Senate committee report on the bill explained that the provisos of § 2 (a) throw "upon any who claim the benefit of those exceptions the burden of showing that their case falls within them." 12 We think that the language of the Act, and the legislative history just cited, show that Congress meant by using the words "discrimination in price" in § 2 that in a case involving competitive injury between a seller's customers the Commission need only prove that a seller had charged one purchaser a higher price for like goods than he had charged one or more of the purchaser's competitors.13 This construction is consistent with the first sentence of § 2 (a) in which it is made unlawful "to discriminate in price between different purchasers of commodities of like grade and quality, where either or any of the purchases involved in such discrimination are in commerce . . . and where the effect of such discrimination may be . . . to injure, destroy, or prevent competition with any person who either grants or knowingly receives the benefit of such discrimination, or with customers of either of them: ." Third. It is argued that the findings fail to show that respondent's discriminatory discounts had in fact caused. 11 Javierre v. Central Altagracia, 217 U. S. 502, 507-508 and cases cited. 12 Sen. Rep. No. 1502, 74th Cong., 2d Sess. 3. See also 80 Cong. Rec. 3599, 8241, 9418. 13 See Moss, Inc. v. Federal Trade Comm'n, 148 F. 2d 378, 379, holding that proof of a price differential in itself constituted "discrimination in price," where the competitive injury in question was between sellers. See also Federal Trade Comm'n v. Cement Institute, 333 U. S. 683, 721-726. Opinion of the Court. 334 U.S. injury to competition. There are specific findings that such injuries had resulted from respondent's discounts, although the statute does not require the Commission to find that injury has actually resulted. The statute requires no more than that the effect of the prohibited price discriminations "may be substantially to lessen competition . . . or to injure, destroy, or prevent competition." After a careful consideration of this provision of the Robinson-Patman Act, we have said that "the statute does not require that the discriminations must in fact have harmed competition, but only that there is a reasonable possibility that they 'may' have such an effect." Corn Products Co. v. Federal Trade Comm'n, 324 U. S. 726, 742. Here the Commission found what would appear to be obvious, that the competitive opportunities of certain merchants were injured when they had to pay respondent substantially more for their goods 14 14 This language is to be read also in the light of the following statement in the same case, discussing the meaning of § 2 (a), as contained in the Robinson-Patman Act, in relation to § 3 of the Clayton Act: "It is to be observed that § 2 (a) does not require a finding that the discriminations in price have in fact had an adverse effect on competition. The statute is designed to reach such discriminations 'in their incipiency,' before the harm to competition is effected. It is enough that they 'may' have the prescribed effect. Cf. Standard Fashion Co. v. Magrane-Houston Co., 258 U. S. 346, 356–357. But as was held in the Standard Fashion case, supra, with respect to the like provisions of § 3 of the Clayton Act, prohibiting tying clause agreements, the effect of which 'may be to substantially lessen competition,' the use of the word 'may' was not to prohibit discriminations having the mere possibility' of those consequences, but to reach those which would probably have the defined effect on competition." 324 U. S. at 738; see also United States v. Lexington Mill Co., 232 U. S. 399, 411. The Committee Reports and Congressional debate on this provision of the Robinson-Patman Act indicate that it was intended to have a broader scope than the corresponding provision of the old Clayton Act. See note 18 infra. 37 Opinion of the Court. than their competitors had to pay. The findings are adequate. Fourth. It is urged that the evidence is inadequate to support the Commission's findings of injury to competition.15 As we have pointed out, however, the Commission is authorized by the Act to bar discriminatory prices upon the "reasonable possibility" that different prices for like goods to competing purchasers may have the defined effect on competition.16 That respondent's quantity discounts did result in price differentials between competing purchasers sufficient in amount to influence their resale prices of salt was shown by evidence. This showing in itself is adequate to support the Commission's appropriate findings that the effect of such price discriminations "may be substantially to lessen competition . . and to injure, destroy, and prevent competition." The adequacy of the evidence to support the Commission's findings of reasonably possible injury to competition from respondent's price differentials between competing carload and less-than-carload purchasers is singled out for special attacks here. It is suggested that in considering the adequacy of the evidence to show injury to competition respondent's carload discounts and its other 15 After discussing all of respondent's discriminations, the Commission stated: "The Commission finds that the effect of the discriminations in price, including discounts, rebates, and allowances, generally and specifically described herein may be substantially to lessen competition in the line of commerce in which the purchaser receiving the benefit of said discriminatory price is engaged and to injure, destroy, and prevent competition between those purchasers receiving the benefit of said discriminatory prices, discounts, rebates, and allowances and those to whom they are denied." 16 The statute outlaws any discrimination the effect of which "may be substantially to lessen competition . . . or to injure . . . competition with any person who either grants or knowingly receives the benefit of such discrimination, or with customers of either of them: ... Opinion of the Court. 334 U.S. quantity discounts should not be treated alike. The argument is that there is an obvious saving to a seller who delivers goods in carload lots. Assuming this to be true, that fact would not tend to disprove injury to the merchant compelled to pay the less-than-carload price. For a ten-cent carload price differential against a merchant would injure him competitively just as much as a ten-cent differential under any other name. However relevant the separate carload argument might be to the question of justifying a differential by cost savings, it has no relevancy in determining whether the differential works an injury to a competitor. Since Congress has not seen fit to give carload discounts any favored classification we cannot do so. Such discounts, like all others, can be justified by a seller who proves that the full amount of the discount is based on his actual savings in cost. The trouble with this phase of respondent's case is that it has thus far failed to make such proof. It is also argued that respondent's less-than-carload sales are very small in comparison with the total volume. of its business" and for that reason we should reject the Commission's finding that the effect of the carload discrimination may substantially lessen competition and may injure competition between purchasers who are granted and those who are denied this discriminatory discount. To support this argument, reference is made to the fact 17 Respondent introduced testimony and exhibits intended to show that only one-tenth of one per cent of its sales were made at lessthan-carload prices. It appears that this figure relates only to a single one-year period and was obtained by lumping together statistics on respondent's sales of table salt along with those on sales of its other products, such as salt tablets, coarse rock salt, and sal soda. Since this proceeding is concerned only with discounts on table salts, these figures are of dubious value. Furthermore, they are limited to sales in respondent's Chicago area, whereas respondent carried on a nation-wide business. 37 Opinion of the Court. that salt is a small item in most wholesale and retail businesses and in consumers' budgets. For several reasons we cannot accept this contention. There are many articles in a grocery store that, considered separately, are comparatively small parts of a merchant's stock. Congress intended to protect a merchant from competitive injury attributable to discriminatory prices on any or all goods sold in interstate commerce, whether the particular goods constituted a major or minor portion of his stock. Since a grocery store consists of many comparatively small articles, there is no possible way effectively to protect a grocer from discriminatory prices except by applying the prohibitions of the Act to each individual article in the store. Furthermore, in enacting the Robinson-Patman Act, Congress was especially concerned with protecting small businesses which were unable to buy in quantities, such as the merchants here who purchased in less-than-carload lots. To this end it undertook to strengthen this very phase of the old Clayton Act. The committee reports on the Robinson-Patman Act emphasized a belief that § 2 of the Clayton Act had "been too restrictive, in requiring a showing of general injury to competitive conditions . . . The new provision, here controlling, was intended to justify a finding of injury to competition by a showing of "injury to the competitor victimized by the discrimination." 18 Since there was evidence sufficient to 18 In explaining this clause of the proposed Robinson-Patman Act, the Senate Judiciary Committee said: "This clause represents a recommended addition to the bill as referred to your committee. It tends to exclude from the bill otherwise harmless violations of its letter, but accomplishes a substantial broadening of a similar clause now contained in section 2 of the Clayton Act. The latter has in practice been too restrictive, in requiring a showing of general injury to competitive conditions in the line of commerce concerned; whereas the more immediately important concern is in injury to the competitor victimized by the |