concurring:
I concur entirely in the Court’s opinion, including the ruling that under ordinary *179principles of mootness, our dismissal of the appeal does not effect the vacatur of the district court opinion. I write separately in order to point out, with utmost respect for the district judge, that in the fullness of caution he may wish to consider on remand the vacatur of his own opinion and the passing of this case^ to another district judge.
This case concerns the ranking of two HW projects on a priority funding list of projects that the City of New York' submitted to HUD. This appeal was taken from an opinion holding that the City of New York down-ranked the HW projects in retaliation for HW’s political opposition to the Mayor rather than because (as is undisputed) the City’s computer system reflected that HW had been cited for financial non-responsibility. The district court’s preliminary injunction, which required the City to re-rank HW’s projects, was rendered moot when HUD funded New York City programs for the homeless at an increased level that obviated the ranking priorities.
The decision of HUD that mooted this appeal was made so close to oral argument that the appellate panel was required to thoroughly prepare the case. In the course of my review, I was struck in particular by two findings made by the district court in support of its (preliminary) ruling on the merits:
First, the district court relied in part on its finding that the Mayor of New York City has delayed an unusual length of time before deciding HW’s appeal from the determination of non-responsibility, and expressly took “judicial notice that, historically, mayors have handled these appeals expeditiously, due to the grave consequences that a determination of non-responsibility has on the finances and vitality of the beleaguered entity.” This finding is the only finding that anyone presumed to dislike HW was involved in any way in the decision to down-rank its projects.
Second, the district court found that it is “not uncommon” for “under-funded and inadequately financed not-for-profit entities serving the poor” to have accounting deficiencies, including “mis-ap-plying funds to projects, failing to maintain proper records, and ... dereliction] in reporting.”
Whether or not these findings can possibly be supported by judicial notice, see Fed.R.Evid. Rule 201(b) (limiting judicial notice to facts “not subject to reasonable dispute”); see also International Star Class Yacht Ass’n v. Tommy Hilfiger USA, Inc., 146 F.3d 66, 70 (2d Cir.1998) (noting that “[c]are must be taken that the requisite notoriety exists [and][e]very reasonable doubt upon the subject should be resolved promptly in the negative”) (quoting Brown v. Piper, 91 U.S. 37, 43, 23 L.Ed. 200 (1875)), it appears that in taking judicial notice of such things, the district judge was drawing upon his own experience and service in City government as corporation counsel in the administration of Mayor Edward I. Koch in the early 1980s. In a dispute that bristles with public controversy, as all the filings in this Court emphasize, it may be undesirable for the fact-finding to be done by a judge (i) who was a high-level official in the administration of another Mayor of the City, and (ii) who in the fact-finding process is evidently drawing (via judicial notice) upon his pre-judicial experience in that post. See e.g., 21 Charles Alan Wright & Kenneth W. Graham, Jr., Federal Practice and Procedure: Evidence § 5104 at 235 (Supp. 1998) (discussing the “danger that the judge will confuse his own knowledge with judicial notice”); 9 J. Wigmore, Evidence in Trials at Common Law § 2569, at 723 (J. Chabourn rev. ed. 1981) (“[T]he judge is not to use from the bench, under the guise of judicial knowledge, that which he knows only as an individual observer outside of court.”).
For that reason, I invite the district court to consider whether vacatur of the opinion and transfer of this case to another *180judge may be a prudent course. That is a decision that lies entirely in the sound discretion of the district judge.