Opinion for the Court filed Per Curiam.
Dissenting opinion filed by Chief Judge WALD.
PER CURIAM:
Appellants, International Union, United Automobile, Aerospace and Agricultural Implement Workers of America, UAW, et al. sued the Secretary of the United States Department of Labor (“Secretary”), challenging regulations providing waivers for recovery of nonfault overpayments on the ground that they were not in conformity with the 1981 amendments to the 1974 [83]*83Trade Act, 19 U.S.C. § 2315(a)(1) (1988). The district court dismissed the suit, holding that the Secretary’s regulations fell within the broad discretion Congress entrusted to her. We now affirm.
I. Statutory Framework
The Trade Act of 1974 (“the Act”) provides federally-funded Trade Adjustment Assistance (“TAA”) benefits to employees laid off as a result of foreign competition. Trade Act of 1974, Pub.L. No. 93-618, 88 Stat.1978 (1975) (codified as amended at 19 U.S.C. §§ 2101-2495 (1988)). The Act directs the Secretary to provide benefits to eligible workers upon certification that their former employer has been adversely affected by foreign competition. Eligible employees may file for TAA benefits in the form of job training and placement services and weekly payments of Trade Readjustment Allowances (“TRA”). 19 U.S.C. §§ 2271 et seq. Under the Act, the Secretary may enter into agreements with state agencies, which act as the “agent of the United States.” 19 U.S.C. §§ 2311(a), 2313(a). These state agencies process applications from individual claimants and determine whether they are entitled to receive benefits and services under the Act. 19 U.S.C. § 2311(a). The Act also provides a mechanism for the Secretary to recoup overpayments — payments made to eligible workers in excess of their statutory entitlements. 19 U.S.C. § 2315. As initially enacted, the Act provided for recovery of overpayments in cases of fraud, but was silent as to recovery of overpayments where fraud was not involved.
In 1981, in response to pressure to cut program spending, Congress amended the Act. Omnibus Budget Reconciliation Act of 1981 (“OBRA”), Pub.L. No. 97-35, Title XXV, § 2509, 95 Stat. 887 (1981); see also 127 Cong.Rec. 13860 (1981) (statement by Sen. Danforth predicting 87% reduction in TAA program spending); Trade Adjustment Assistance for Workers, Firms, and Communities: Hearings Before the Sub-comm. on Trade of the House Comm, on Ways and Means, 97th Cong., 1st Sess. 43 (1981) [hereinafter House Hearings] (initial estimate of 77% cut in TAA spending). The amendments require cooperating state agencies to recover nonfault overpayments in addition to fraudulent overpayments. However, the amendments also allow state agencies to waive recovery of nonfault overpayments according to guidelines established by the Secretary. 19 U.S.C. § 2315(a)(1). Section 2315(a)(1) on recovery of overpayments states:
If a cooperating State agency, the Secretary, or a court of competent jurisdiction determines that any person has received any payment under this part to which the person was not entitled ... such person shall be liable to repay such amount to the State agency or the Secretary, as the case may be, except that the State agency or the Secretary may waive such repayment if such agency or the Secretary determines, in accordance with guidelines prescribed by the Secretary, that—
(A) the payment was made without fault on the part of such individual, and
(B) requiring such repayment would be contrary to equity and good conscience.
19 U.S.C. § 2315(a)(1).
The Secretary originally construed the statute to afford the option of not promulgating regulations pertaining to the waiver of overpayments and directed state agencies not to grant such waivers. When appellants challenged the Secretary’s refusal to issue waiver guidelines, the district court prohibited the Secretary and the state agencies from recouping any non-fraudulent overpayments until the Secretary had issued final waiver guidelines. International Union, United Automobile, Aerospace, and Agricultural Implement Workers of America, et. al. v. Donovan, 554 F.Supp. 1172, 1173, 1175 (D.D.C.1983). In compliance with the District Court’s ruling in UAW, the Secretary issued proposed rules concerning the recovery of TAA over-payments on March 4, 1983. 48 Fed.Reg. 9,444 (1983). After receiving and considering comments on the proposed rule, the Secretary issued final guidelines on February 22, 1986 (51 Fed.Reg. 45,840 (1986)) [84]*84which became effective January 21, 1987. 20 C.F.R. § 617.55 (1989). Under these regulations, the Secretary or the state agency may waive recoupment of excess TAA benefits when a waiver applicant establishes that (1) she was not at fault for the overpayment, and (2) requiring her to repay the excess benefits would be “contrary to equity and good conscience.” 20 C.F.R. § 617.55(a) (1989). The regulations also state that forcing repayment would be contrary to equity and good conscience if such repayment causes “extraordinary financial hardship” — i.e., the inability to obtain minimal necessities for a period of at least thirty days.1
The guidelines provide inter alia that states need not consider waiver applications for nonfraudulent overpayments at all. The Secretary interprets the language of § 2315(a)(1) that a state agency “may waive” repayment as purely discretionary; states may simply choose not to waive such repayment under any circumstance. 51 Fed.Reg. 45,845 (1986).2
Appellants challenge the Secretary’s regulations on two grounds. First, appellants claim that the Secretary’s interpretation of the “may waive” language, which allows states to refuse to entertain all waiver requests, is contrary to Congress’ intent. Second, appellants allege that the Secretary’s construction of the “equity and good conscience” criteria for waivers is so narrow as to constitute an unlawful reading of that phrase. We reject both challenges.
II. Analysis
A. The Secretary’s Interpretation of “May Waive”
Appellants first contend that the congressional directive that “the State agency or the Secretary may waive such repayment” is not discretionary and must be interpreted to require states to consider waivers of nonfraudulent overpayments. We disagree.
The appropriate standard of review of the Secretary’s interpretation of the statute is stated in Chevron USA, Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984). Under Chevron’s familiar two-part test, we first look to see if Congress had a clearly discernible intent on the precise [85]*85question at issue. If so, then that intention must be given effect. If, however, the statute is ambiguous or silent on the issue, then we must determine whether the Secretary’s interpretation is “a permissible construction of the statute.” Chevron, 467 U.S. at 842-43, 104 S.Ct. at 2781-82.
Section 2315(a)(1) provides that if an individual receives a nonfault overpayment, “such person shall be liable to repay such amount to the State agency or the Secretary, ... except that the State agency or the Secretary may waive such repayment” if the guidelines are met. 19 U.S.C. § 2315(a)(1) (emphasis added).
Appellants contend that the “may waive” phrase, read in context, merely introduces the rest of the sentence which defines the criteria that an applicant must meet to obtain a waiver; i.e., if the guidelines are met, the state agency must grant the waiver. Appellants’ interpretation, however, puts an intolerable strain on the ordinary meaning of the text. Effectively, appellants read the word “may” as if it were “shall,” despite the usual presumption that “may” confers discretion, while “shall” imposes an obligation to act. See, e.g., Haig v. Agee, 453 U.S. 280, 294 n. 26, 101 S.Ct. 2766, 2775 n. 26, 69 L.Ed.2d 640 (1981) (holding that the language “may grant passports” is discretionary); Southern Railway Co. v. Seaboard Allied Milling Corp., 442 U.S. 444, 455, 99 S.Ct. 2388, 2394, 60 L.Ed.2d 1017 (1979) (stating that “the Commission may ... order a hearing” can only be construed as discretionary). Indeed, the Fourth Circuit has upheld the Secretary’s interpretation of the term “may waive” as permissive under a similar overpayment provision in the Federal Supplemental Compensation Act, Pub.L. No. 97-248, Title VI, § 606(a)(2)(A), 96 Stat. 702, 705-06 (codified at 26 U.S.C. § 3304 note (1988)). Hicks v. Cantrell, 803 F.2d 789, 793 (4th Cir.1986).3 The Supreme Court has also interpreted a number of statutory waiver provisions, featuring language similar to § 2315(a)(1), as permissive. Califano v. Yamasaki, 442 U.S. 682, 693-94 n. 9, 99 S.Ct. 2545, 2553-54 n. 9, 61 L.Ed.2d 176 (1979) (interpreting “there shall be no adjustment ... or recovery” from persons qualifying for a waiver, as mandatory, in contrast to permissive language such as an agency “may waive,” recovery “may be waived,” or recovery “is not required”). The Secretary’s discretionary interpretation of the “may waive” language is well-rooted in the plain meaning of § 2315(a)(1).
Considering the frequency with which it uses the two words, Congress can be expected to distinguish between “may” and “shall.” In this very section, Congress provided that the individual “shall be liable to repay” an overpayment, but that the state agency “may waive such repayment” (emphasis added). We can assume, therefore, that if Congress meant that the state agency “shall waive such repayment” under certain conditions, it would have said so unambiguously. See Hecht Co. v. Bowles, 321 U.S. 321, 326-27, 64 S.Ct. 587, 590, 88 L.Ed. 754 (1944) (holding that the use of “may” and “shall” in the same sentence of a statute implies that each was used purposefully); Persinger v. Islamic Republic of Iran, 729 F.2d 835, 843 (D.C.Cir.), cert. denied, 469 U.S. 881, 105 S.Ct. 247, 83 L.Ed.2d 185 (1984) (the use of different language in different parts of the same statute creates a strong inference that different meanings are intended).
It is of course true, as appellants remind us, that the ordinarily discretionary overtones of the word “may” “can be defeated [86]*86by indications of legislative intent to the contrary or by obvious inferences from the structure and purpose of the statute.” United States v. Rodgers, 461 U.S. 677, 706, 103 S.Ct. 2132, 2149, 76 L.Ed.2d 236 (1983). Appellants accordingly argue here that the legislative history of § 2315(a)(1) indicates that Congress intended “may waive” to be mandatory rather than permissive. However, the legislative history they cite to support this claim is thin. It consists of a few short passages suggesting that Congress sought to “provide” for waivers, surrounded by dozens of pages emphasizing the legislators’ focus on cost-cutting. Probably the best support for appellants’ contention is the statement in the House Hearings by then-Secretary of Labor Donovan that § 2315(a)(1) “provides for waivers where equitable.” House Hearings at 14; see S.Rep. No. 139, 97th Cong., 1st Sess. 536 (1981) U.S.Code Cong. & Admin.News 1981, p. 396 [hereinafter S.Rep. No. 139] (Donovan’s statement reprinted); S.Rep. No. 103, 97th Cong., 1st Sess. 6 (1981) [hereinafter S.Rep. No. 103] (same). However, “provides for waivers” as easily can mean that the section permits waivers as it can mean that the section requires them. The House reports, on the other hand, contain no such language. Instead, they state that recovery of over-payments is “subject to discretionary waiver by the State agency,” lending strong support to the Secretary’s interpretation. H.R.Rep. No. 143, 97th Cong., 1st Sess. 30 (1981) [hereinafter H.R.Rep. No. 143], reprinted in H.R.Rep. No. 158, 97th Cong., 1st Sess., vol. III, at 278 (1981) [hereinafter H.R.Rep. No. 158]. Secretary Donovan himself, in proposing the legislation, stated that § 2315(a)(1) “broadens the present authority to recover overpayments,” as a means of recouping program funds and cutting costs, indicating that cost-cutting was the primary objective of the Administration-sponsored amendments. House Hearings at 12, 14; see S.Rep. No. 103 at 6 (same); S.Rep. No. 139 at 536 (same); H.R. Rep. No. 143 at 30 (same); H.R.Rep. No. 158, vol. III, at 278 (same).
Nor does the structure or context of the statute outside of § 2315(a)(1) indicate something other than that states were to have discretion whether to allow waivers. Appellants cite § 2315(a)(2), which states that deductions from future benefits may be made “[u]nless an overpayment is otherwise recovered, or waived under paragraph (1),” as evidence that Congress intended that waivers would be available whenever the specified conditions were met. But that is a weak reed indeed. Merely listing waiver as one eventuality that would ward off a deduction does not come even close to suggesting that states are obliged to consider waiver requests. Appellants also assert that § 2315(c), which states that “no repayment may be required, and no deduction may be made, under this section until a determination under subsection (a)(1) of this section by the State agency or the Secretary ... has been made,” uniformly requires the opportunity for a hearing on waiver eligibility before an overpayment can be recovered. The § 2315(c) hearing, however, concerns only the issue of whether overpayments were received in the first place, and does not implicate waivers at all.
Finally, appellants contend that discretionary waivers are inconsistent with the overall purpose of the statute. Appellants argue that Congress had three goals when it enacted § 2315(a)(1): to broaden recovery of overpayment and provide for waivers where equitable,4 to create a national rule on recovery and waiver,5 and to pro[87]*87tect program funds. Whether or not broad purposes can trump plain language, we find that Congress expressed a single predominant purpose with respect to § 2315(a)(1): “to broaden recovery of over-payments in order to protect program funds.” H.R.Rep. No. 143 at 30; H.R.Rep. No. 158, vol. III, at 278; see also Letter from Raymond J. Donovan to Thomas P. O’Neill, Jr. and George Bush, March 28, 1981, reprinted in House ^Hearings at 12. The Secretary’s regulations are entirely consistent with that expressed purpose, as well as the overall purpose of the amendments to “make expenditure reductions in accordance with the budget reconciliation process.” H.R.Rep. No. 143 at 1.
In sum, the Secretary’s interpretation of § 2315(a)(1) allowing the states an option on entertaining waivers is a permissible one.
B. The Secretary’s Interpretation of “Equity and Good Conscience”
Appellants also challenge those portions of the Secretary’s regulations that define the criteria for determining whether recoupment “would be contrary to equity and good conscience,” within the meaning of § 2315(a)(1)(B). Examining these regulations under the test stated in the Administrative Procedure Act, 5 U.S.C. § 706, and guided by the Supreme Court’s instruction in Chevron, we are satisfied that the Secretary’s interpretation is not “arbitrary, capricious, or manifestly contrary to the statute.”
Section 2315(a)(1) provides that, if the state elects to grant waivers of repayment at all, an individual may qualify where (A) “the [overpayment was made without fault on the part of such individual,” and (B) “requiring such repayment would be contrary to equity and good conscience.” 19 U.S.C. § 2315(a)(1). Congress did not define “equity and good conscience.” Instead, it delegated that responsibility to the Secretary, stating that waiver eligibility should be determined “in accordance with guidelines prescribed by the Secretary.” 19 U.S.C. § 2315(a)(1).
Under the Secretary’s regulations, “financial hardship” is the key. The regulations list these factors:
(1) Whether the overpayment was the result of a decision on appeal, whether the State agency had given notice to the individual that the case has been appealed and that the individual may be required to repay the overpayment in the event of a reversal on appeal, and whether recovery of the overpayment will not cause extraordinary and lasting financial hardship to the individual.
(2) Whether recovery of the overpayment will not cause extraordinary financial hardship to the individual [where the overpayment was not the result of a decision on appeal]____
20 C.F.R. § 617.55(a)(2)(ii)(A). The Secretary defines “extraordinary financial hardship” to exist where
recovery of the overpayment would result directly in the individual’s loss of or inability to obtain minimal necessities of food, medicine, and shelter for a substantial period of time; and an extraordinary and lasting financial hardship shall be extraordinary as described above and may be expected to endure for the foreseeable future.
§ 617.55(a)(2)(ii)(C)(l). The regulations further define a “substantial period of time” as thirty days, and the “foreseeable future” as three months. § 617(a)(2)(ii)(C)(2). In calculating the extent of financial hardship, the regulations direct the state agency to consider all potential income and potential cash resources of the individual and the individual’s family. Id.
Appellants argue that the Secretary’s definition is contrary to the plain meaning of the words “equity and good conscience.” This claim is a difficult one to make, as “equity and good conscience” has no standardized meaning, but rather is a formulation of flexible and varied application. One standard legal reference defines the term [88]*88“equity” as “denotpng] the spirit and habit of fairness, justness, and right dealing which would regulate the intercourse of pndividuals].” Black’s Law Dictionary 484 (5th ed. 1979), cited in Gilíes v. Department of Human Resources Dev., 11 Cal.3d 313, 322 n. 10, 113 Cal.Rptr. 374, 380 n. 10, 521 P.2d 110, 116 n. 10 (1974).
It goes without saying that persons of good will may differ widely as to what is “fair,” “just” and consistent with “right dealing” in a given context. The fairness and justness of decisions made by this Court, for example, regularly occasion disagreement between successful and unsuccessful litigants. Just so, in the present case. Those who have received money because of the government’s error and through no fault of their own may think it not consistent with right dealing to require them to pay the money back, all the more so when they spent the money not knowing they had no entitlement to it. Nonetheless, the Secretary remains responsible to the taxpayers who paid in the funds paid out through bureaucratic error, and to a Congress and Executive determined to make drastic cuts in TAA program spending. See supra at 754, 757. Given the Administration’s cost-cutting policy, a policy approved and adopted by Congress, see supra at 757, the Secretary can hardly be taken greatly to task for making waiver of recoupment a tightly limited exception to the pay-it-back main rule.
In face of the elastic nature of “equity and good conscience,” and the obligation of courts to heed the context in which the words appear, appellants argue that the Secretary’s interpretation is unreasonably narrow. Appellants rely, particularly, on the Eighth Circuit’s decision in Groseclose v. Bowen, 809 F.2d 502 (8th Cir.1987). In that case, the state sought to recover overpayment of a child’s insurance benefits by deducting the overpayment amount from the father’s retirement insurance benefits, even though the father did not himself receive, and had no knowledge of, the overpayment. Groseclose, 809 F.2d at 503. The regulation successfully challenged in Groseclose looked to one factor only, detrimental reliance. The father necessarily had not relied on receipts of which he was unaware. The Secretary maintained that, because the father was unable to show detrimental reliance, recoupment was not barred by “equity and good conscience” as defined in the regulations.
The Groseclose court looked first to the Social Security Act prescription in question, which expressly prohibited the Secretary from seeking repayment when considerations of “fault” and “equity and good conscience” weighed in favor of granting a waiver. The court further found, upon consulting the relevant legislative history, that Congress intended “to make recovery more equitable ... broadening] the Secretary’s authority to waive adjustments] or recovery of overpayment.” Groseclose, 809 F.2d at 505-06 (quoting 1967 U.S.Code Cong. & Admin.News 2834, 3096). In light of this underlying purpose to facilitate waiver, the court found the Secretary’s definition unreasonably narrow, and held that recoupment in the factual scenario at issue was contrary to “equity and good conscience.” Id.; accord Quinlivan v. Secretary of Health & Human Servs., 916 F.2d 524 (9th Cir.1990).
We do not dwell on the question whether we would follow the Groseclose court were we confronted with the same statute. It suffices to note a highly significant distinction between the Social Security Act command at issue in Groseclose and the provisions of the Trade Act at issue in the present case. While the Groseclose court relied on the evident congressional intent, expressed in the Social Security Act text and history, to facilitate waiver,6 the legislative history of the Trade Act amendments indicates that Congress passed § 2315(a)(1) in a determined effort to prompt broader recovery of overpayments, and thereby serve the legislators’ primary, cost-cutting, [89]*89objective. See, e.g., House Hearings at 14; S. Rep. No. 139 at 536-37. Thus, while the Social Security Act prohibits recoupment of overpayments when inconsonant with “equity and good conscience,” the Trade Act initially instructs recoupment of all over-payments, allowing waiver only on the state’s election and within limits entrusted to the Secretary’s formulation.
Our conclusion that the Secretary has not abused the large discretion Congress gave her is supported by the Secretary’s implementation of a similar provision in the Federal Supplemental Compensation Act of 1982. That statute authorizes state agencies to require repayment of overpayments, except that the agency “may waive” repayment where the individual is without fault and repayment would be contrary to equity and good conscience. 26 U.S.C. § 3304 note (1988). The Secretary’s regulations pursuant to this provision are virtually identical to the regulations at issue here; her regulations for the Compensation Act state that “equity and good conscience” permits dispensation where recovery would prevent the recipient from obtaining minimal necessities of food, medicine, and shelter for thirty days; further, those regulations define “foreseeable future” to mean three months. 49 Fed.Reg. 4,271, 4,281 (1984). This example indicates both that the Secretary’s present interpretation of “equity and good conscience” is not a unique one, and that the Secretary appropriately differentiates between statutes that require waiver and those that simply tolerate some forgiveness of indebtedness.
Because Congress has made an express delegation of authority to the Secretary, this Court may determine only whether the agency’s regulations are rationally connected to the legislative ends. See Chevron, 467 U.S. at 844, 104 S.Ct. at 2782. “When a challenge to an agency construction of a statutory provision, fairly conceptualized, really centers on the wisdom of the agency’s policy, rather than whether it is a reasonable choice within the gap left open by Congress, the challenge must fail.” Chevron, 467 U.S. at 866, 104 S.Ct. at 2793; accord American Hosp. Ass’n v. Bowen, 834 F.2d 1037 (D.C.Cir.1987); Greensboro Lumber Co. v. FERC, 825 F.2d 518, 522 (D.C.Cir.1987). Under this standard, we need not find that the Secretary has reached an unassailable conclusion based on detailed economic analysis; we need find only that the Secretary’s definition is reasonably related to the legislature’s design. The Secretary could doubtless have been more generous in her definition of “equity and good conscience” consistent with the statute. However, her present tight rule is reasonably related to Congress’ primary intent drastically to reduce the costs of a supplemental unemployment compensation program. For this reason, we find that the Secretary’s interpretation of “equity and good conscience” is a permissible, context-driven construction of the 1981 Trade Act alteration.
III. Conclusion
As we conclude that the district court correctly determined that the Secretary acted within her discretion, we affirm the judgment.