Under § 215 of the Social Security Act, as added, 64 Stat. 506, and amended, 42 U.S.C. § 415 (1970 ed. and Supp. V), old-age insurance benefits are computed on the basis of the wage earner's "average monthly wage" earned during his "benefit computation years" which are the "elapsed years" (reduced by five) during which the wage earner's covered wages were highest. Until a 1972 amendment, "elapsed years" depended upon the sex of the wage earner. Section 215(b)(3) prescribed that the number of "elapsed years" for a male wage earner would be three higher than for an otherwise similarly situated female wage earner; for a male, the number of "elapsed years" equaled the number of years that elapsed after 1950 and before the year in which he attained age 65; for a female the number of "elapsed years" equaled the number of years that elapsed after 1950 and before the year in which she attained age 62.*fn1 Thus, a male born in 1900
would have 14 "elapsed years" on retirement at age 65 but a female born in the same year would have only 11.*fn2 Accordingly, a female wage earner could exclude from the computation
of her "average monthly wage" three more lower earning years than a similarly situated male wage earner could exclude. This would result in a slightly higher "average monthly wage" and a correspondingly higher level of monthly old-age benefits for the retired female wage earner.*fn3 A single-judge District Court for the Eastern District of New York, on review under § 205(g) of the Social Security Act, 42 U.S.C. § 405(g), of a denial, after hearing, of appellee's request that the more favorable formula be used to compute his benefits, held that, on two grounds, the statutory scheme violated the equal protection component of the Due Process Clause of the Fifth Amendment: (1) that to give women who reached age 62 before 1975 greater benefits than men of the same age and earnings record was irrational,*fn4 and (2) that in any event the 1972 amendment was to be construed to apply retroactively, because construing the amendment to give men who reach age 62 in 1975 or later the benefit of the 1972 amendments but to deny older men the same benefit would render the amendment irrational, and therefore unconstitutional. 413 F. Supp. 127 (1976). We reverse.
To withstand scrutiny under the equal protection component of the Fifth Amendment's Due Process Clause, "classifications
by gender must serve important governmental objectives and must be substantially related to achievement of those objectives." Craig v. Boren, 429 U.S. 190, 197 (1976). Reduction of the disparity in economic condition between men and women caused by the long history of discrimination against women has been recognized as such an important governmental objective. Schlesinger v. Ballard, 419 U.S. 498 (1975); Kahn v. Shevin, 416 U.S. 351 (1974). But "the mere recitation of a benign, compensatory purpose is not an automatic shield which protects against any inquiry into the actual purposes underlying a statutory scheme." Weinberger v. Wiesenfeld, 420 U.S. 636, 648 (1975). Accordingly, we have rejected attempts to justify gender classifications as compensation for past discrimination against women when the classifications in fact penalized women wage earners, Califano v. Goldfarb, ante, at 209 n. 8; Weinberger v. Wiesenfeld, supra, at 645, or when the statutory structure and its legislative history revealed that the classification was not enacted as compensation for past discrimination. Califano v. Goldfarb, ante, at 212-216 (plurality opinion), 221-222 (STEVENS, J., concurring in judgment); Weinberger v. Wiesenfeld, supra, at 648.
The statutory scheme involved here is more analogous to those upheld in Kahn and Ballard than to those struck down in Wiesenfeld and Goldfarb. The more favorable treatment of the female wage earner enacted here was not a result of "archaic and overbroad generalizations" about women. Schlesinger v. Ballard, supra, at 508, or of "the role-typing society has long imposed" upon women, Stanton v. Stanton, 421 U.S. 7, 15 (1975), such as casual assumptions that women are "the weaker sex" or are more likely to be child-rearers or dependents. Cf. Califano v. Goldfarb, supra; Weinberger v. Wiesenfeld, supra. Rather, "the only discernible purpose of [ § 215's more favorable treatment is] the permissible one of redressing our society's longstanding disparate treatment of women." Califano v. Goldfarb, ante, at 209 n.8.
The challenged statute operated directly to compensate women for past economic discrimination. Retirement benefits under the Act are based on past earnings. But as we have recognized: "Whether from overt discrimination or from the socialization process of a male-dominated culture, the job market is inhospitable to the woman seeking any but the lowest paid jobs." Kahn v. Shevin, 416 U.S., at 353. See generally id., at 353-354, and nn. 4-6. Thus, allowing women, who as such have been unfairly hindered from earning as much as men, to eliminate additional low-earning years from the calculation of their retirement benefits works directly to remedy some part of the effect of past discrimination.*fn5 Cf. Shlesinger v. Ballard, supra, at 508.
The legislative history of § 215(b)(3) also reveals that Congress directly addressed the justification for differing treatment of men and women in the former version of that section and purposely enacted the more favorable treatment for female wage earners to compensate for past employment discrimination against women. Before 1956, the sexes were treated equally by § 215(b)(3); the computation it required turned on the attainment of "retirement age," which was then defined in 42 U.S.C. § 416(a) (1952 ed.) as ...