concurring in part and dissenting in part:
¶ 52 I concur in the majority’s response to certified question No. 2. I also concur in that section of the majority opinion titled “Justice Martone’s Dissent,” dealing with a procedural matter wholly unrelated to the substantive issues in this case.
¶ 53 I respectfully dissent from that part of the majority opinion responding to certified question No. 1. The response undermines legitimate employer expectations in a remarkable departure from traditional at-will employment principles. It transforms the conventional employer-employee contract from one that is unilateral (performance of an act in exchange for a promise to pay) to one that is bilateral (a promise for a promise). The decision is unsupported by Arizona precedent and unwarranted as a matter of law.
¶ 54 The majority exacts from the certified question the premise that the employment relationship between the Demasse plaintiffs and ITT is “no longer at-will.” I disagree. A single contract term in a policy manual may, while it exists, become an enforceable condition of employment, but it does not alter the essential character of the relationship. In my view, ITT, as the party unilaterally responsible for inserting it into the manual may, on reasonable notice, exercise an equal right to remove it.
*516¶ 55 For purposes of this discussion, it is assumed the reverse-seniority layoff provision became part of the “employment contract” years earlier when ITT initially placed it into the policy manual and that it remained a part of the “contract” as long as it remained a part of the manual. The simple question put to us is whether ITT may unilaterally bring about its removal and thereafter be free of any prospective reverse-seniority obligation in the event of a layoff. That question does not catapult the case beyond the reach of at-will employment principles.
¶ 56 In accordance with the doctrine of Leikvold v. Valley View Community Hospital, 141 Ariz. 544, 688 P.2d 170 (1984), ITT added a contract disclaimer to its 1989 handbook: “[N]othing contained herein shall be construed as a guarantee of continued employment.” In the same handbook, ITT expressly reserved “the right to amend, modify, or cancel this handbook, as well as any or all of the various policies, rules, procedures, and programs outlined within it.” Each of the Demasse plaintiffs signed a certification acknowledging that the new policy had been received and reviewed.
¶ 57 The “at-will” status of the DemasseITT contract both before and after the 1989 amendments is confirmed by at least two factors: (1) the contract was always one of indefinite duration, and (2) the Demasse employees had the absolute right to quit at any time.
¶ 58 In Wagner v. City of Globe, 150 Ariz. 82, 722 P.2d 250 (1986), we determined that “[e]very employment contract for an indefinite term is presumed to be terminable at will.” Wagner, 150 Ariz. at 84, 722 P.2d at 252; see also Wagenseller v. Scottsdale Mem’l Hosp., 147 Ariz. 370, 374, 710 P.2d 1025, 1029 (1985) (defining an at-will employee as “one hired without specific contractual term”). We further declared that an employee’s ability to “quit at any time” was a central aspect of at-will employment. See Wagner, 150 Ariz. at 85, 722 P.2d at 253. The at-will relationship may, of course, be replaced by an implied-in-fact contract, but this occurs only when there is “proof of an implied-in-fact promise of employment for a specific duration.” Wagenseller, 147 Ariz. at 376, 710 P.2d at 1031. Here, no durational component ever attached to ITT’s reverse-seniority layoff provision or to any other aspect of the employment relationship, and ITT always afforded its employees the unrestricted right to terminate at any time. Accordingly, I view the employment arrangement between the Demasse plaintiffs and ITT as a continuing, at-will relationship.
¶ 59 The right to quit in opposition to changed policies, despite the majority’s view, is properly characterized as a right. It is an inherent feature of at-will employment. The Washington Supreme Court forcefully made this point in Thompson v. St. Regis Paper Co., 102 Wash.2d 219, 685 P.2d 1081 (1984).
When the employment relationship is not evidenced by a written contract and is indefinite in duration, the parties have entered into a contract whereby the employer is essentially obligated to only pay the employee for any work performed. In this contractual relationship, the employer exercises substantial control over both the working relationship and his employees by retaining independent control of the work relationship. Thus, the employer can define the work relationship. Once an employer takes action, for whatever reasons, an employee must either accept those changes, quit, or be discharged. Because the employer retains this control over the employment relationship, unilateral acts of the employer are binding on its employees and both parties should understand this rule.
Id. at 1087 (emphasis added).
¶ 60 In Wagner, this court explained the relationship:
Employment contracts, particularly those which would be considered at-will, are the best and most typical examples of unilateral contracts. Unlike a bilateral contract, a unilateral contract does not require mutuality of obligation; but there is sufficient consideration in the form of services rendered. This is true despite the fact that the employee may quit at any time.
Id., 150 Ariz. at 85, 722 P.2d at 253 (citing 1A A. Corbin, Corbin on Contracts § 152, at 13-*51714 (1963)) (citation omitted) (emphasis added).
¶ 61 Wagner contemplates that modification of the at-will relationship typically occurs through distribution of an employee handbook, just as ITT anticipated in the instant case:
Because the at-will employment relationship is contractual, it can be modified by the parties at any time just as other contracts can be modified.
One widely accepted means of modifying the at-will contract is use or publication of personnel manuals, guides, or rules by employers. An employer’s represen-tations contained in a personnel manual “can become terms of the employment contract and limit an employer’s ability to discharge his or her employees,” even though the personnel policies were not bargained for at the time of hiring.
Id. at 85-86, 722 P.2d at 253-54 (citation omitted) (emphasis added). We thus declared explicitly that employers have authority to modify at-will contracts and are bound by terms added after the employment relationship has begun.
¶ 62 The corollary, however, is also true: just as employers are bound currently by the terms of existing policy manuals, employees must be bound prospectively by amendments to the manual, even though a particular amendment was not bargained for at the point of hire. Hogue v. Cecil I. Walker Machinery Co., 189 W.Va. 348, 431 S.E.2d 687, 691 (1993); In re Certified Question (Bankey) v. Storer Broadcasting Co., 432 Mich.438, 443 N.W.2d 112, 120 (1989); Pine River State Bank v. Mettille, 333 N.W.2d 622, 626-27 (Minn.1983). When ITT modified its policy manual in 1989 by adding the contract disclaimer and the power to amend, and offered continuing employment to employees having received notice and having signed the acknowledgment, the employees effectively gave their acceptance to the amendment by continuing to work. Moreover, in 1993, when ITT revised its layoff policy, the employees had known for four years that such change could occur.1
¶ 63 The majority overlooks another point. Just as at-will employees are unilaterally free to quit at any time, employers may be unilaterally forced by economic circumstance to curtail or shut down an operation, something employers have the absolute right to do. When the employer chooses in good faith, in pursuit of legitimate business objectives, to eliminate an employee policy as an alternative to curtailment or total shutdown, there has been forbearance by the employer. Such forbearance constitutes a benefit to the employee in the form of an offer of continuing employment. The employer who provides continuing employment, albeit under newly modified contract terms, also provides consideration to support the amended policy manual.
¶ 64 Such is the nature of the at-will contract; consideration is found in the employer’s offer of continuing employment, and the employee accepts the offer by his continued performance. Wagner, 150 Ariz. at 85, 722 P.2d at 253. Under the unilateral theory, continuing performance by the employee at a *518job that the employer continues to offer, subject to modified terms, manifests acceptance of the new terms. See id.; Pine River, 333 N.W.2d at 626-27; see also Mattison v. Johnston, 152 Ariz. 109, 112-13, 730 P.2d 286, 289-90 (App.1986) (continued employment is sufficient consideration for the modification of an at-will employment contract by amendment added subsequent to the date of hire).
¶ 65 The majority imposes a bilateral principle on the at-will relationship by holding that in order for ITT to eliminate the reverse-seniority layoff policy, some form of new consideration, in addition to an offer of continuing employment, is necessary to support each individual employee’s assent to the amended manual. The majority’s approach effectively mandates that ITT, in order to free itself of future reverse-seniority obligations, would be required to give a wage increase, a one-time bonus, or some other new benefit to the employees with the explicit understanding that such benefit was given in exchange for the amendment to the policy manual. This becomes artificial because it is foreign to the unilateral at-will relationship and, as a practical matter, it leaves the employer unable, at least in part, to manage its business. I disagree with the proposition that “new” consideration is necessary.
¶ 66 The majority further asserts that ITT’s exercise of the unilateral right to amend the handbook renders the employer’s original reverse-seniority promise illusory. Once again, I disagree. An illusory promise is one which by its own terms makes performance optional with the promisor whatever may happen, or whatever course of conduct he may pursue. 17A Am.Jur.2d Contracts § 3 at 27 (1991). The reverse-seniority promise was not illusory because it was not optional with ITT as long as it remained a part of ITT’s handbook policy. During the years of its existence, it was fully enforceable. Moreover, the promise was genuine because it was applicable to all ITT employees, not merely a select few. Leikvold, 141 Ariz. at 548, 688 P.2d at 174.
¶ 67 The same notion applies, of course, to any promise given in a unilateral relationship. It remains in full force until it is withdrawn or amended. If the ITT promise of reverse-seniority were illusory, so also would every unilateral promise become illusory on the basis that such promise could be withdrawn or amended.
¶ 68 The majority opinion produces the net result that the reverse-seniority layoff policy, as a permanent term of the “employment contract” with respect to any employee who at any time worked under it, gains parity with a negotiated collective bargaining agreement having a definite term, usually three years. In fact, the ITT policy would have force and effect even greater than a collective agreement because its existence, as to the Demasse plaintiffs and others similarly situated, becomes perpetual. This result grants preferential treatment to every employee who worked under the policy but denies such treatment to employees hired after its removal. A collective bargaining agreement is bilateral, and to impose a bilateral relationship on simple at-will employment is, in my view, an attempt to place a square peg in a round hole. Inevitably, this will impair essential managerial flexibility in the workplace. It will also cause undue deterioration of traditional at-will principles.
¶ 69 Two decisions cited by the Ninth Circuit in the certification order, both from Arizona, appropriately apply the foregoing principles. In Chambers v. Valley National Bank, 721 F.Supp. 1128 (D.Ariz.1988), an employee, terminated without cause after sixteen years of employment, alleged breach of contract by the defendant bank. The manual in effect at the time of termination defined plaintiffs employment as “at-will.” The employee argued that the bank was barred from unilaterally changing a policy of “for cause” termination because the at-will disclaimer did not appear in previous versions of the employment handbook. The court disagreed:
The inclusion of the disclaimer in the 1985 publications may best be considered an offer of a modification to a unilateral contract of employment, which plaintiff accepted by continuing her employment with defendant. Although an “employer is contractually bound to observe ... [published] policies until they are modified *519or withdrawn,” he is free to modify his personnel policies prospectively.
Chambers, 721 F.Supp. at 1131-32 (emphasis added).
¶ 70 Similarly, Bedow v. Valley National Bank, 5 IER Cases 1678 (D.Ariz.1988), holds:
[A]s a matter of basic contract law, each successive version of defendant’s personnel policy manual modifies and supersedes prior issued versions. Courts in other jurisdictions have specifically so held, while courts in Arizona have implicitly done so as in Mattison v. Johnston, 152 Ariz. 109, 730 P.2d 286 (App.1986) where the court ruled that continued employment constituted sufficient consideration to enforce a new term or provision of employment in an “at will” employment relationship.
Bedow, 5 IER Cases at 1680 (emphasis added).
¶ 71 Leikvold itself is not to the contrary. [Personnel manuals can become part of employment contracts. Whether any particular personnel manual modifies any particular employment-at-will relationship and becomes part of the particular employment contract is a question of fact.
Leikvold, 141 Ariz. at 548, 688 P.2d at 174. These cases identify the at-will relationship as contractual and hold that a handbook is subject to unilateral change and can thus modify that relationship. Conversely, the majority roots its analysis in the erroneous notion that a single contract term — layoff by reverse-seniority — supplants the at-will relationship when in fact the removal of one term of that relationship is all that was intended. Neither Leikvold, Wagner, nor Wagenseller supports such a departure from established law.
¶ 72 Courts have adopted various legal theories upholding the at-will relationship in a similar context. Some have theorized that distribution of an amended employee handbook constitutes an offer “to replace” the existing contract with a new contract. In Lee v. Sperry Corp., 678 F.Supp. 1415 (D.Minn.1987), a Minnesota district court applied Pine River principles and concluded that distribution of a new handbook negated the existence of a former implied contractual layoff term:
“[A]n original employment contract may be modified or replaced by a subsequent unilateral contract. The employee’s retention of employment constitutes acceptance of the offer of a unilateral contract; by continuing to stay on the job, although free to leave, the employee supplies the necessary consideration for the offer.” Although Pine River dealt directly with the transformation from at-will employment to employment based on unilateral contract, the principle seems equally applicable to the opposite transformation. Here, plaintiff worked for over three years after receiving the handbook with the employment contract disclaimer. During that time, he was provided with salary increases and other improvements in employment benefits.
Id. at 1418 (quoting Pine River, 333 N.W.2d at 627) (emphasis added). The majority opinion in the instant ease ignores Pine River ’s “replacement of contract” language, cited in Lee, though this court cited Pine River approvingly in Wagenseller. See Wagenseller, 147 Ariz. at 381, 710 P.2d at 1036; see also Restatement (Second) of Contracts § 279 & cmt. a (1981) (“A substituted contract is one that is itself accepted by the obligee in satisfaction of the original duty and thereby discharges it. A common type of substituted contract is one that contains a term that is inconsistent with a term of an earlier contract between the parties.”).
¶73 Moreover, failure to include in a first-distributed handbook a provision reserving the power to modify or amend does not alter the analysis. See Ferrera v. A.C. Nielsen, 799 P.2d 458, 460 (Colo.App.Ct.1990); Bankey, 443 N.W.2d at 120 (“[w]e hold today that an employer may make changes in a written [handbook] policy applicable to its entire workforce or to specific classifications without having reserved in advance the right to do so.”).
¶ 74 Other courts have upheld the employer’s right to amend by express rejection of strict rules of contract modification. The Michigan Supreme Court adopted this theory, answering a certified question strikingly similar to the question presented here and *520concluding that an employer must have unilateral ability to amend handbook provisions:
In a typical situation, where employment is for an indefinite duration, the unilateral contract framework provides no answer to the question: When will the act bargained for by the employer be fully performed? The answer to that question depends on the characterization of the “act” for which the promise is exchanged. If the “act” is simply a day’s work (for a day’s wage), then ... [t]he employer’s offer is renewed each day, and each day’s performance by the employee constitutes a new acceptance and a new consideration. But such a characterization can be strikingly artificial. New employers and employees begin each day contemplating whether to renew or modify the employment contract in effect at the close of work on the previous day.
The major difficulty [with the idea that a “meeting of the minds” must occur to alter an implied in fact contract] as applied to the question before us is that the contractual obligation which may not be modified without mutual assent ... could have arisen without mutual assent____Under circumstances where “contractual rights” have arisen outside the operation of normal contract principles, the application of strict rules of contractual modification may not be appropriate.
Bankey, 432 Mich. 438, 443 N.W.2d 112, 116 (1989) (emphasis added).
¶ 75 One commentator refers to the Ban-key approach as an “administrative law model”:
The employer, like an agency, is bound by its rules, but always remains free to change the rules prospectively through proper procedures. Agencies have wide discretion in amending or revoking them regulations, as long as they meet the requirements set by administrative law for issuing them in the first place. But until modified or revoked, the regulations must be followed by the issuing agency. This is a good model for implied-in-fact contracts of employment security....
The general idea is well accepted in other areas of labor and employment law. Henry H. Perritt, Jr., Employee Dismissal Law & Practice § 4.44 (3d ed.1992) (citations omitted).
¶ 76 In the case at bar, the majority applies the hypertechnical approach rejected by the Bankey court. Yet, the concept of prior notice, central to the Bankey model, was stated in Dover Copper Mining Co. v. Doenges, 40 Ariz. 349, 357, 12 P.2d 288, 291-92 (1932) (finding employment at-will service contracts “are terminable at pleasure by either party, or at most upon reasonable notice”). Consistent with Dover, this court stated in Leikvold that the at-will rule “is at best a rule of construction.” See Leikvold, 141 Ariz. at 547, 688 P.2d at 173.
¶ 77 Principles of equity and pragmatic reason have also governed the employer’s unilateral right to change an implied-in-fact term in a handbook. The federal district court, applying Arizona law in Bedow, correctly asserted that the last-distributed handbook controls employment conditions and trumps prior inconsistent handbook terms:
Any other conclusion would create chaos for employers who would have different contracts of employment for different employees depending upon the particular personnel manual in force when the employee was hired. Such a result would effectively discourage employers from either issuing employment manuals or subsequently upgrading or modifying personnel policies.
Bedow, 5 IER Cases at 1680 (emphasis added).
¶ 78 Michigan’s Bankey decision cited similar concerns:
Were we to ... hold[ ] that once an employer adopted a policy of discharge-for-cause, such a policy could never be changed short of successful renegotiation with each employee who worked while the policy was in effect, the uniformity stressed in Toussaint would be sacrificed.... If an employer had amended its handbook from time to time, as often is the ease, the employer could find itself obligated in a variety of different ways to any number of different employees, depending on the modifications which had been adopted and the extent of the work *521force turnover. Furthermore, ... many employers would be tied to anachronistic policies in perpetuity merely because they did not have the foresight to anticipate the Court’s Toussaint decision by expressly reserving at the outset the right to make policy changes.
Bankey, 443 N.W.2d at 119-20 (emphasis added). See Woolley v. Hoffmann-La Roche, Inc., 99 N.J. 284, 491 A.2d 1257, 1266 n. 8 (1985) (a variety of unforeseen business and economic conditions that can and do arise, require the ability to adapt to prospective needs). See also Fleming v. Borden, Inc., 316 S.C. 452, 450 S.E.2d 589, 595 (1994) (“[T]he employer-employee relationship is not static. Employers must have a mechanism which allows them to alter the employee handbook to meet the changing needs of both business and employees.”); Brooks v. Trans World Airlines, Inc., 574 F.Supp. 805, 810 (D.Colo.1983) (“TWA’s concern that it not be shackled with a workforce it is unable to reduce without fear of wrongful discharge litigation is understandable____”); Ferrera, 799 P.2d at 460 (“It would be unreasonable to think that an employer intended to be permanently bound by promises in a handbook, leaving it unable to respond flexibly to changing conditions.”). Although the rationales have differed among these opinions, a common theme emerges — recognition that an employer cannot be perpetually bound by a handbook promise for which the employees did not specifically bargain at the outset of the relationship.2
¶79 In addition to the error of contract construction, the majority applies inapposite authority to bolster the most critical aspect of its reasoning. The opinion cites extensively to Toth v. Square D Co., 712 F.Supp. 1231 (D.S.C.1989), a federal case applying South Carolina law. Yet the Supreme Court of South Carolina squarely rejected Toth by allowing unilateral change in an employment manual subject to reasonable notice by the employer to the employees. See Fleming v. Borden, Inc., 316 S.C. 452, 450 S.E.2d 589, 595 (1994) (“[W]e reject the bilateral concepts enunciated in Toth.”) (emphasis added).3
¶80 Thompson v. Kings Entertainment Co., 674 F.Supp. 1194 (E.D.Va.1987), also cited by the majority and- referring to Virginia law, is rejected by the decision in Progress Printing Co., Inc. v. Nichols, 244 Va. 337, 421 S.E.2d 428 (1992), where the Supreme Court of Virginia held that an acknowledgment, signed by an employee, superseded and replaced a provision in an employee handbook that an employee could be discharged only “for cause.”4
¶81 Torosyan v. Boehringer Ingelheim Pharmaceuticals, Inc., 234 Conn. 1, 662 A.2d 89 (1995) is also inapposite. The Torosyan court noted that representations were made specifically to a particular employee during *522the job interview that established at the outset a required move from California to Connecticut and an employment relationship whereby the employee could be terminated only for cause. The court understandably refused to allow the employer to modify such terms through general dissemination of an employee handbook. These terms were specific to the employee in question and not part of the terms of employment applicable to employees generally. The opposite is true in the instant case.
¶ 82 Finally, the majority cites to Yeazell v. Copins, 98 Ariz. 109, 402 P.2d 541 (1965), as principal proof that its opinion “blazes no new ground.”5 Contrary to our facts, Yeazell addressed the legislature’s ability to alter vested pension terms after employment had begun. That issue is vastly different from the one presented here. In Yeazell, we held that legal vesting of such rights occurs at the time employment begins. See id. at 115, 402 P.2d at 545. In contrast, the Ninth Circuit observed in the instant case that “nothing in Arizona law ... would treat rights to layoff in a certain order as a vested benefit.” See Demasse y. ITT Corp., 111 F.3d 730, 733 (9th Cir.1997). Vested rights present a fundamentally different issue. See Bankey, 443 N.W.2d at 120 n. 17 (noting that a unilateral change of vested rights involves a different analysis than when only nonvested “rights” are at issue).6
¶83 The majority’s answer to the certified question will frustrate the legitimate expectations of both employers and employees. The notion that one term in an employee handbook — a reverse-seniority layoff term— can be perpetually binding as to some but not all employees will effectively undermine Wagner, Wagenseller, and Leikvold on which employers have relied for years. The opinion unduly punishes ITT and other employers similarly situated. We said in Leikvold that employers should place contract disclaimer language in their handbooks to preserve the at-will relationship. ITT responded by inserting such language. We should leave it at that.
. Courts are virtually universal in accepting the precept that an employer is entitled, unilaterally, to modify handbook terms. See, e.g., Ryan v. Dan’s Food Stores, Inc., 972 P.2d 395, 401 (Utah 1998) (continued work with knowledge of changed employment conditions renders previous, contradictory handbook provisions inapplicable); Johnston v. Panhandle Coop. Ass’n, 225 Neb. 732, 408 N.W.2d 261, 266 (1987) C [W]here an at-will employee retains employment with knowledge of new or changed conditions, the new or changed conditions may become a contractual obligation. The employee’s retention of employment constitutes acceptance of the offer of a unilateral contract; by continuing to stay on the job, although free to leave, the employee supplies the necessary consideration for the offer.”); Cook v. Heck's Inc., 176 W.Va. 368, 342 S.E.2d 453, 459 (1986) (“We agree with those courts that have found valuable consideration in the continued labor of workers who have in the past foregone their right to quit at any time. We conclude that a promise of job security contained in an employee handbook distributed by an employer to its employees constitutes an offer for a unilateral contract; and an employee's continuing to work, while under no obligation to do so, constitutes an acceptance and sufficient consideration to make the employer’s promise binding and enforceable.”); see also Thomas G. Fischer, Annotation, Sufficiency of Notice of Modification in Terms of Compensation of At-Will Employee Who Continues Performance to Bind Employee, 69 A.L.R.4th 1145 (1989).
. In contrast, the majority effectively holds that once the at-will relationship is modified and supplanted by an implied-in-fact contract term, that term becomes a permanent obligation, no longer subject to change by unilateral notice and acceptance manifested by continued work on the part of the work force. The majority would require a fully negotiated elimination of the implied-in-fact term with each employee, supported by new consideration flowing to each employee. In support, the majority cites case law from Wyoming and Illinois. See Brodie v. General Chemical Corp., 934 P.2d 1263 (Wyo.1997); Doyle v. Holy Cross Hosp., 186 Ill.2d 104, 237 Ill.Dec. 100, 708 N.E.2d 1140 (1999); and Robinson v. McKinley Comm. Serv. Inc., 19 F.3d 359 (7th Cir.1994). Quite clearly, these cases support the majority position in the instant case. But they reflect no more than a minuscule minority in a vast sea of cases and traditional law to the contrary. I believe they are wrongly decided.
. The Fleming decision also moots the majority's reference to Bishop Realty & Rentals, Inc. v. Perk, Inc., 292 S.C. 182, 355 S.E.2d 298 (App.1987), a decision of South Carolina's appellate court that preceded Fleming.
. The majority argues that Progress Printing is "not on point,” asserting that the court analyzed two conflicting documents as a single contract. I believe the majority reads the case incorrectly. The trial court treated two documents, a handbook and a later-issued acknowledgment form, as one contract en route to concluding that the handbook promise of written notice before termination was still in force. On appeal, the Supreme Court of Virginia found the two documents in conflict, and thus not part of the same contract. The court ruled the later-issued acknowledgment erased the promise of written notice found in the handbook, reversing the trial court’s legal holding and its underlying factual conclusion that the two documents were part of one contract. This result cannot be reconciled with Thompson, a federal diversity case purporting to apply Virginia law.
. Three other cases cited to support the "no ' ground-blazing” argument — Angus Med. Co. v. Digital Equip. Corp., 173 Ariz. 159, 840 P.2d 1024 (App.1992); Nationwide Resources Corp. v. Massabni, 134 Ariz. 557, 658 P.2d 210 (App.1982); Coronado Co., Inc. v. Jacome's Dep’t Store, Inc., 129 Ariz. 137, 629 P.2d 553 (App.1981) — do not deal with at-will employment but instead deal with modification of bilateral executoiy contracts, a form of contractual relationship which does not exist in the instant case by reason of the indefinite duration of employment and the employees’ right to quit at any time.
. Even in the higher stakes realm of vested rights under pension plans, two recent federal circuit courts have rejected the bilateral concepts espoused in our majority opinion. See Sprague v. General Motors Corp., 133 F.3d 388 (6th Cir.1998) (rejecting the argument that GM’s handbook created a bilateral contract, which could not be unilaterally modified, that would force GM to pay medical benefits to employees after retirement); Frahm v. The Equitable Life Assurance Soc'y, 137 F.3d 955 (7th Cir.1998) (rejecting bilateral contract arguments and allowing unilateral change in employee medical plan benefits). Those decisions produced a harsher result than that faced by the Demasse plaintiffs.