I
We decide a question of first impression: whether under the Sarbanes-Oxley Act of 2002 (“Sarbanes-Oxley”), 15 U.S.C. § 78u-3 (“Section 1103”), certain termination payments to high-level corporate officials are “extraordinary payments,” subject to involuntary retention in an escrow account compelled by court order. Because there was no evidence as to what would be an ordinary payment under comparable circumstances, we conclude that the district court erroneously determined certain payments proposed to be made by Defendant Gemstar-TV Guide International Inc. (“Gemstar”) to Intervenors-Appellants Yuen and Leung (hereafter Appellants) were “extraordinary payments” within the meaning of section 1103 of Sarbanes-Ox-ley. We vacate the district court’s order and remand for further proceedings consistent with this opinion.
In view of our ruling, we do not decide whether section 1103 of Sarbanes-Oxley is unconstitutionally vague, or operates in an unconstitutionally retroactive manner.
II
FACTS
On August 14, 2002, Gemstar, a Delaware corporation, announced that it was *1089auditing the operations of its Technology and Licensing Sector and Interactive Platform Sector after finding that 2001 revenues and related amortization for these sectors had been overstated by some $40 million. On November 7, 2002, Gemstar announced plans to restructure its management and corporate governance.
As part of the restructuring plans, Gemstar entered into negotiations for termination agreements with its Chief Executive Officer (“CEO”), Dr. Henry Yuen, and its Chief Operating Officer (“COO”) and Chief Financial Officer (“CFO”), Elsie Ma Leung. Dr. Yuen’s termination agreement provided for a “termination fee” of $22,452,640, an additional $7,030,778 in unpaid salary, bonuses, and unused vacation time, and 5,274,519 shares of restricted stock. Ms. Leung was to receive a termination fee of $6,957,953, an additional $1,209,695 in unpaid salary, bonuses, and unused vacation time, 1,126,504 shares of common stock, and 353,680 shares of restricted stock. Additionally, Yuen agreed to serve as the non-executive chairman of the board and Leung agreed to a position as an employee in the international business department. The arrangements for Yuen’s and Leung’s compensation are collectively referred to as the Restructuring Payments.
On October 15, 2002, before the Yuen and Leung termination agreements were in final form, attorneys for the Securities and Exchange Commission (“SEC”) met with counsel for Gemstar, Yuen, and Leung, and requested that the Restructuring Payments be placed in escrow. On October 17, 2002, the SEC ordered a formal investigation into the announced overvaluation of the revenue and profits from some of Gemstar’s sectors. On October 23, 2002, Yuen and Leung notified the SEC that they declined to submit to a voluntary escrow.
On October 28, 2002, as part of its investigation, the SEC issued testimonial subpoenas to Gemstar’s Board of Directors. Yuen and Leung contend that in response to the subpoenas Gemstar sent a draft escrow agreement for the Restructuring Payments to the SEC on November 6, 2002. Hours before the restructuring agreements were to be executed on November 7, 2002, Gemstar informed Yuen and Leung’s attorney that the Restructuring Payments were to be placed in escrow for six months, and that such escrow provision was non-negotiable. Yuen and Leung acceded to the six-month escrow in “side letters” executed that day.
On March 31, 2003, Appellants Yuen and Leung filed a complaint in district court against the SEC, objecting to the escrow, seeking injunctive and declaratory relief, and requesting a temporary restraining order to unblock and dissolve the escrow to allow the restructuring payments to be made. According to a declaration by Appellants’ counsel, “Gemstar is contractually obligated to release the Restructuring Payments to Plaintiffs on May 6, 2003.” Appellants’ counsel also maintained that the escrow impermissibly interfered with Yuen’s and Leung’s property rights to receive the Restructuring Payments, and that the escrowed payments did not constitute “extraordinary payments” under section 1103 of Sarbanes-Oxley. Following an April 21, 2003 hearing, the district court denied Appellants’ request for a preliminary injunction, finding that the side letters constituted consent by Yuen and Leung to the initial escrow, set to expire May 6, 2003. The district court did not address whether the restructuring payments qualified as “extraordinary payments” under section 1103.
On May 5, 2003, the SEC filed an application with the district court to place the *1090Restructuring Payments in a 45-day escrow account pursuant to Section 1103. In a declaration filed with the application, an attorney for the SEC described the ongoing investigation of Gemstar. The district court sua sponte ordered the parties to maintain the status quo and requested additional briefing. A hearing was held on May 9, 2003. On May 12, 2003, the district court entered an order granting the SEC’s application to place the Restructuring Payments in escrow and directed the parties to prepare a joint order to effect such escrow. Appellants filed a motion to reconsider the escrow order on May 22, 2003. After a status conference on May 29, 2003, the court denied Appellants’ motion to reconsider and entered the joint order of escrow. The order specifically described the disputed funds as “extraordinary payments” subject to section 1103, and directed that they be held in interest-bearing accounts for 45 days.1
On June 19, 2003, the SEC commenced a civil action in the Central District of California, No. 03-CV-4376, alleging Yuen and Leung had fraudulently inflated Gemstar’s revenue reports by $223 million, in violation of various sections of the Securities Acts of 1933 and 1934. The SEC also filed an application to have the escrow continued indefinitely for the duration of the action against Yuen and Leung.
On June 20, 2003, on the government’s ex parte motion, the district court extended the temporary escrow for an additional 45 days. The district court reiterated its finding that the payments were “extraordinary payments” within the meaning of section 1103, and rejected Appellants’ contentions that the statute was unconstitutionally vague. On June 24, 2003, the district court entered an order directing the maintenance of the escrow for the duration of the SEC’s civil action.
Yuen and Leung filed a notice of interlocutory appeal on July 2, 2003.2 Appellants contend section 1103(1) is void for vagueness; (2) effects an unreasonable seizure of their property in violation of the Fourth Amendment; (3) does not retroactively apply to the payments in this case that had already been contracted to be paid or had already been made prior to the enactment of the statute; and (4) does not apply to the disputed payments, which are not “extraordinary payments” for the purposes of Sarbanes-Oxley.3
Ill
SECTION 1103
Section 1103 of the Sarbanes-Oxley Act gives the SEC authority to ensure that assets of an issuer of securities4 which *1091have been fraudulently obtained are not dissipated during the investigation and litigation of securities fraud cases. See 15 U.S.C. § 78u-3 (2002). Specifically, section 1103 provides that:
[w]henever, during the course of a lawful investigation involving possible violations of the Federal securities laws by an issuer of publicly traded securities or any of its directors, officers, partners, controlling persons, agents, or employees, it shall appear to the Commission that it is likely that the issuer will make extraordinary payments (whether compensation or otherwise) to any of the foregoing persons, the Commission may petition a Federal district court for a temporary order requiring the issuer to escrow, subject to court supervision, those payments in an interest-bearing account for 45 days.
15 U.S.C. § 78u-3(c)(3)(A)(i). Such an order can be secured only with notice and after a hearing, unless “impracticable or contrary to the public interest.” 15 U.S.C. § 78u-3(c)(3)(A)(ii).
Section 1103 authorizes one additional 45-day extension of the temporary escrow order on a showing of good cause. 15 U.S.C. § 78u-3(c)(3)(A)(iv). However, once the subject of an investigation is charged with a securities violation by the commencement of a civil action, “the order shall remain in effect, subject to court approval, until the conclusion of any legal proceedings related thereto, and the affected issuer or other person, shall have the right to petition the court for review of the order.” 15 U.S.C. § 78u-3(c)(3)(B)(i).
Sarbanes-Oxley does not define “extraordinary payments.” The SEC is empowered to adopt regulations for the implementation of Sarbanes-Oxley. See 15 U.S.C. § 78w. To date the SEC has not done so. Neither Congress nor the SEC has given any indication as to the meaning of the words “extraordinary payments.”
IV
STANDARD OF REVIEW
The district court’s escrow order is reviewed for abuse of discretion. See United States v. Cal-Almond, Inc., 102 F.3d 999, 1001 (9th Cir.1996) (affirming denial of motion to impose escrow). The district court abuses its discretion when it applies incorrect legal standards or makes clearly erroneous findings of fact. Id. at 1003. The district court’s interpretation and construction of a federal statute are questions of law reviewed de novo. SEC v. McCarthy, 322 F.3d 650, 654 (9th Cir.2003).
V
ANALYSIS
1. Jurisdiction
As a threshold issue, the SEC has argued that this appeal is moot because the orders specified in the notice of appeal are no longer in effect. Mootness is grounded in the Constitution’s jurisdictional requirement that federal courts can hear only cases involving an actual case or controversy; mootness preempts any determination on the merits. See Cammermeyer v. Perry, 97 F.3d 1235, 1237 (9th Cir.1996). Mootness turns on “whether there exists a present controversy as to which effective relief can be granted.” Village of Gambell v. Babbitt, 999 F.2d 403, 406 (9th Cir.1993) (citation and internal quotation marks omitted). As noted in footnote 2 above, because the court granted Appellants’ motion to amend its notice of appeal to include the district court’s order of June 24, 2003, which extended the escrow until the *1092completion of the underlying litigation, the SEC’s mootness challenge fails.
The parties are in agreement that this court has jurisdiction pursuant to 28 U.S.C. § 1292(a)(1). They characterize the escrow order entered by the district court as an appealable Rule 65 preliminary injunction rather than a non-appealable provisional remedy under Rule 64. See Fed.R.Civ.P. 64, 65. This issue is not free from doubt, for the escrow order was entered as an exercise of an explicit statutory provision, rather than grounded on any traditional equitable considerations such as are normally required for a preliminary injunction. See, e.g., Southwest Voter Registration Educ. Project v. Shelley, 344 F.3d 914, 917-18 (9th Cir.2003) (en banc). We are also mindful that jurisdiction of this court cannot be imposed simply by agreement of the parties. See Owen Equip. & Erection Co. v. Kroger, 437 U.S. 365, 377, n. 21, 98 S.Ct. 2396, 57 L.Ed.2d 274 (1978).
However, in the circumstances of this case, we find that the district court’s order is analogous to a preliminary injunction and we have jurisdiction under section 1292(a). See Cab-Almond, Inc., 102 F.3d at 1001 (exercising section 1292(a)(1) jurisdiction and affirming district court’s order placing contested advertising and promotion assessments in escrow).
2. Statutory Construction
This appeal presents issues of statutory construction of the term “extraordinary payments.” In its June 20, 2003 order, the district court correctly noted, “ ‘extraordinary’ in common parlance essentially means ‘out of the ordinary’ or ‘unusual.’ Unusual, of course, is a comparative adjective that has meaning only in relation to what is ‘usual.’ ” District Court’s June 20, 2003 Memorandum of Decision at 9 (emphasis added).5 This observation has value only if properly applied. Unfortunately, it was not.
“It would seem that, ordinarily, one could determine what was ‘extraordinary’ and ‘abnormal,’ or not normal, only by comparison with what was established to be normal.” Bjelland & Co., Inc. v. United States, 45 Cust. Ct. 435, 442 (Cust.Ct., Jul. 26, 1960) (on appeal for reappraisement of imported goods, affirming customs appraiser’s valuation of good exchanged in the “ordinary course of trade”). Here, plaintiff SEC limited its proof in its section 1103 application to an investigating attorney’s affidavit (Cebeci Declaration, Excerpts of Record at 111-58). The affidavit incontestably established the first element of section 1103: that an SEC investigation was under way. 15 U.S.C. § 78u-3(c)(3)(B)(i).
However, the affidavit — and consequently the record — is completely silent regarding what constituted usual or ordinary payments upon termination of a CEO and Chairman of the Board (Yuen) or COO and CFO (Leung) under the same or similar circumstances to those existing at the time that Appellants ended their employment with Gemstar. Absent any such proof, the district court erroneously substituted two conclusory statements of what was “extraordinary” without concomitant proof of what was “ordinary,” and an SEC filing, required under a standard different from that of section 1103.
First, the district court found that the negotiation of the termination agreements for Appellants was “extraordinary” because of the various groups that participated in the negotiations and because the negotiations occurred over a five-month period. Members of the Board of Di*1093rectors, officers of the corporation, and compensation consultants, accountants, and attorneys for both sides negotiated the restructuring agreements. Nothing in the record suggests this extended negotiation constitutes a deviation from the norm for corporate decision-making of this type. While common experience of the district court might help to determine what is the usual way to negotiate the termination of a lawyer at a law firm or a staff member of the court, common experiences of this kind do not aid judgment in the circumstances of Appellants’ termination at Gemstar.
As the declaration of Appellants’ counsel shows (Excerpts of Record at 15-23), Gemstar-TV Guide was the product of a merger between an off-shore company founded by Appellants and TV Guide, a subsidiary of News Corporation, a large telecommunications company. The corporation’s earnings before interest, taxes, depreciation and amortization were reported as $242.2 million in the last nine months of 2000. Appellants presented uncontradict-ed evidence that revenue-producing strategies of Yuen and Leung differed, if not clashed, with those of News Corp. Appellants were interested primarily in raising revenue attributable to the corporation’s sales, perhaps not coincidentally to raise their own compensation, which was tied to revenue and profits. The minority owners, Gemstar’s current management, were in part interested in publicizing one of their sister corporations through Gems-tar’s operations, without paying Gemstar any advertising revenue. Such a strategy would increase revenues for the sister corporation, but not for Gemstar. As owners and officers in Gemstar, Appellants would not share in the profits of the sister corporation.
In case Yuen or Leung were terminated “without cause,” lengthy and complex employment agreements governed their termination payments (Supplemental Excerpts of Record at 79, 118). Yuen and Leung had three different components for calculation of their Annual Incentive Bonuses. Complex enough when based on the company’s past performance, computations also had to be done for future payments, with the consequent and predictable squabbling over methods for projecting future financial performance.
In view of Gemstar’s revenue structure, the conflicting strategies, and the complex schemes for computation of termination payments, it is not surprising that Gems-tar would require not only releases, but also representations and warranties from the departing employees. Yet, for all the persons involved in the negotiations, not one presented evidence before the district court that the period or mechanics of the negotiations were out of the ordinary in view of the circumstances. Nor, despite the six-month period between commencement of the investigation (October 17, 2002) and the section 1103 hearing (May 9, 2003), was any expert testimony prepared and presented as to the habits and customs of the marketplace — what was “ordinary” — under the same or similar circumstances.6
The second factor on which the district court based its finding that the proposed payments were “extraordinary payments” was their size. See Memorandum of Decision at 19. We agree that such sums are “extraordinary payments” in relation to what federal judges are paid. However, nothing in section 1103 constrains us to look through such a prism.
*1094There is no evidence in the record of what similarly placed officers and board members of corporations of similar revenues and worth are paid upon termination. Such payments may be called “golden parachutes” or “golden handshakes” in the press, but purple prose is not enough to prove a statutory requirement in court. For enforcement of the securities laws of the United States, evidence of what is “usual” under the same or similar circumstances is necessary to distinguish “extraordinary payments” and to order their impoundment in an escrow pursuant to section 1103.
Last, the district court found it significant that after the termination contracts were finalized, defendant Gemstar chose to report the terms in a Form 8-K filing. A Form 8-K filing is required from an “issuer of securities when substantial events occur ...” Scherk v. Alberto-Culver Co., 417 U.S. 506, 528 n. 6, 94 S.Ct. 2449, 41 L.Ed.2d 270 (1974). In this era of heightened corporate vigilance, it is not surprising that Gemstar management should choose to make this report upon the termination of the founders of the company, who were being paid millions of dollars on departure in an amount approximating 15% of the previous year’s revenues. But, a discretionary corporate disclosure is not an admission that the company has paid an “extraordinary” amount. In any case, there was also no evidence of whether other “issuers” had made similar reports for similar sums paid to similarly departing upper management under the same or similar circumstances. A “substantial event” may or may not coincide with an “extraordinary payment.” Only evidence of comparable events and circumstances can tell us.
Instead of objective evidence, what we have here is the district court’s conjecture as to what would have been “ordinary” or “usual” negotiations for termination payments, conjecture as to what the size should have been of such payments and conclusions drawn from filings made under different standards. The bases used by the district court to judge the negotiations, the payments, and the filing were “irreducibly subjective.” cf. Nuñez v. San Diego, 114 F.3d 935, 943 (9th Cir.1997) (considering vagueness challenge to loitering ordinance).
The district court did not need to rely on such subjective bases. Legislation which uses relative adjectives to proscribe activities is not unknown to the law. Statutes and law prohibit “excessive” verdicts (CAL. CIV. PROC. CODE § 657; Fed.R.Civ.P. 59) and sanction “unreasonable” behavior (CAL. CIV. CODE § 1714; Restatement (Second) of Torts, § 281). It is not beyond the judiciary’s capacity to interpret and apply statutes which prohibit “excessive” or “unreasonable” amounts. Trial and appellate courts are called upon to do so every day.7 As to “excessive,” see *1095State Farm Ins. Co. v. Campbell, 538 U.S. 408, 123 S.Ct. 1513, 1519-20, 155 L.Ed.2d 585 (2003). But in doing so, the courts are guided by precepts of proportionality and precedent.
Less often, courts are asked whether some remuneration constitutes “extraordinary payment.” An example is the line of cases which determines whether payments made by a corporation to an employee is deductible from gross income as an “ordinary and necessary” business expense, or is an “extraordinary payment” disallowed as a deduction. See, e.g., LabelGraphics, Inc. v. Commissioner of Internal Revenue, 221 F.3d 1091, 1096 (9th Cir.2000); Elliotts, Inc. v. Commissioner Internal Revenue, 716 F.2d 1241, 1242 (9th Cir.1983).
Whether the adjective is “excessive,” “negligent” or “extraordinary,” the cases in which those terms appear use similar processes of judgment. The trier-of-fact determines first what constitutes “adequate compensation,” “reasonable care,” or “customary or ordinary payments.” Such determinations require evidence which consists of similar factual situations which can be compared to the case at hand. If the case at hand falls outside the bounds permitted in the comparison cases, that result is deemed “excessive,” “negligent,” or “extraordinary.”
Absent a definition from Congress, “we interpret the words using their ‘ordinary, contemporary, and common meaning[s].’ ” United States v. Migi, 329 F.3d at 1088. As is suggested in the district court’s order, the statute’s qualifying term “extraordinary” necessarily implies proof that the payments deviate from the ordinary. See Chalmers v. City of Los Angeles, 796 F.2d 1205, 1215 (9th Cir.1985) (holding that counsel’s success was not extraordinary in light of the evidence presented at trial and the non-complexity of the case). A reasonable interpretation of the common meaning of section 1103 requires that the questioned payments be out of the ordinary. Not mere government assertion, but proof by admissible objective evidence of what is ordinary is necessary to allow a court to determine what is extraordinary. Such evidence was not adduced in the district court; that absence requires the reversal of the judgment of the district court.
VI
CONCLUSION
For the reasons stated, Appellants’ appeal from the June 24, 2003 escrow order is granted, and that order is vacated and remanded for proceedings consistent with this opinion.
The clerk is directed to stay the mandate in this case for 14 calendar days following the filing of this opinion, should the government seek to file a renewed section 1103 request consistent with the standard of proof outlined in this opinion.
VACATED AND REMANDED; the Clerk shall stay the mandate for 14 days after the filing of this opinion.
. The record, does not indicate location of the escrow or the interest rate applied to the escrow accounts.
. The notice of appeal specified that Yuen and Leung were appealing only the temporary orders of May 12, 2003, May 29, 2003, and June 20, 2003. The notice of appeal did not include the district court's currently operative order of June 24, 2003. We granted Yuen's and Leung’s motion to amend their notice of appeal to include the June 24, 2003 order.
. At this time, only one other case involving an asset freeze under Sarbanes-Oxley had been published, See SEC v. Healthsouth Corp., 261 F.Supp.2d 1298 (N.D.Ala.2003). Health-south does not specifically address what constitutes sufficient evidence of "extraordinary payments” under section 1103. The district court in Healthsouth construed the SEC’s escrow request as an equitable motion for preliminary injunction and rejected the imposition of an escrow on the ground that the SEC could not show likely success on the merits. The court concluded that "no other basis for granting the relief requested by the SEC exists.” Healthsouth Corp., 261 F.Supp.2d at 1317.
.An issuer is defined as "any person who issues or proposes to issue any security ..." 15 U.S.C. § 78c(a)(8). It is undisputed that Gemstar was, at all times relevant, an issuer *1091of securities within the meaning of Sarbanes-Oxley.
. The district court correctly resorted to "common parlance” in interpreting section 1103. United States v. Migi, 329 F.3d 1085, 1088 (9th Cir.2003).
. This observation is not to be taken as a direction that, on remand, expert testimony is either required or admissible. As always, the choice of evidence is a matter for the parties. The admission of expert evidence is, in the first instance, a matter for the district court. See Fed.R.Evid. 702.
. For instance, courts are often called upon to determine whether awards of attorney’s fees are "reasonable.” See Pennsylvania v. Delaware Valley Citizens’ Council for Clean Air, 478 U.S. 546, 562, 106 S.Ct. 3088, 92 L.Ed.2d 439 (1986). "The fee applicant has the burden of producing satisfactory evidence, in addition to the affidavits of its counsel, that the requested rates are in line with those prevailing in the community for similar services of lawyers of reasonably comparable skill and reputation.” Jordan v. Multnomah County, 815 F.2d 1258, 1263 (9th Cir.1987) (citation omitted). The proffered evidence of reasonable fees must constitute "more than a mere 'rough guess’ or initial approximation of the final award to be made.” Pennsylvania, 478 U.S. at 564, 106 S.Ct. 3088.
Likewise, courts daily determine what are "extraordinary” fees in probate courts across the country. But, unlike the district court, those probate courts have elaborate statutes, rules of procedure and case authority to guide them in determining what services by estate representatives are "ordinary” (and covered *1095by the statutory fees) and what expenses are “extraordinary,” conferring entitlement to added fees. See e.g. CAL. PROB. CODE §§ 10801, 10811; CAL. COURT R. 7.702; In re Fulcher’s Estate, 234 Cal.App.2d 710, 718, 44 Cal.Rptr. 861 (1965).