concurring:
Although I agree that the Board has failed to explain adequately its imposition of a Gis-sel bargaining order, the record demonstrates that the Board made sufficient findings regarding management turnover at the hotel. While the ALJ first suggested that “management turnover,” in general, should not “affeet[] the validity of a bargaining order,” he proceeded to address this factor and found the hotel’s evidence unconvincing. The Board, in turn, adopted these findings regarding management turnover and clarified the underlying reasoning sufficiently. Thus, in my view, the principal issue requiring further consideration on remand is the evidence of substantial employee turnover at Flamingo since the election.
Both the Board and the ALJ considered the hotel’s evidence of management turnover and offered particularized explanations, why this evidence does not make a bargaining order an inappropriate remedy. At the hearing before the ALJ, the hotel introduced evidence showing that eight of the twenty-one supervisors found to have committed unfair labor practices were no longer e.mployed by the hotel.1 With the exception of William J. Sherlock, the hotel’s President, the ALJ discounted the significance of these departures because the supervisors’ unlawful conduct was “minor in nature” or had only a minimal impact on employees in comparison to the substantial number of other unfair labor practices committed by hotel management. Additionally, the ALJ explained that “the mere fact that Sherlock is now gone has lessened effect when it is known that basic labor relations policies are devised by corporate Hilton executives and not necessarily the property president at some given point in time.”
In order to clarify this assessment, the Board pointed to Jim Anderson, Hilton’s Corporate Senior Vice President for Labor Relations and Personnel Administration, as one of the remaining corporate executives who “played a major role in orchestrating the [hotel’s] unlawful campaign against the Union.” Anderson “primarily developed the overall extent of [the hotel’s] countering campaign” against the Union organization drive, was one of the “select group” that helped choose the labor relations consulting firm hired to combat the union, and directed the on-site managers implementing the campaign. Although Anderson was not personally involved in the majority of unfair labor practices committed by on-site supervisors, he directly participated in some of the hotel’s more pervasive unlawful conduct. He was involved, for example, in the hotel’s decision *1176to improve employee health benefits prior to the election and was responsible for determining the timing of the announcement. He also' approved an increase in wages for hourly employees, which affected more than half of the employees in the hotel department. In the ALJ’s words: “Anderson was delegated the responsibility to determine its timing, and knowing well how it might interplay with the Union’s campaign he directed it to be implemented immediately.” Cf. Electrical Prods. Div. of Midland—Ross Corp. v. NLRB, 617 F.2d 977, 987 (3d Cir.1980).
Regardless of .the extent of Anderson’s personal complicity in the hotel’s unlawful attempts to influence the election, the Board used his conduct to illustrate its general view that responsibility for the hotel’s actions reached higher levels of Hilton’s corporate management. Anderson and other Hilton executives set the basic labor policies for Hilton’s various casino-hotels and specifically approved some of the actions taken by the hotel’s supervisors. Thus, the .Board concluded that turnover in on-site management is unlikely to improve the chances for a fair rerun election as long as Hilton corporate policy remains unchanged and guided by executives such as Anderson. See NLRB v. Berger Transfer & Storage Co., 678 F.2d 679, 694 (7th Cir.1982); NLRB v. Anchorage Times Publ’g Co., 637 F.2d 1359, 1370 (9th Cir.1981).
This conclusion is bolstered by the Board’s experience in other cases involving similar unlawful attempts by Hilton to interfere with union elections at its Nevada hotel-casinos. See, e.g., Reno Hilton Resorts, 320 NLRB 197, 197-98 (1995); Reno Hilton Resorts Corp., 319 NLRB 1154, 1154, 1165-66 (1995); Flamingo Hilton Reno, 317 NLRB 361, 361 (1995), aff'd mem, 95 F.3d 1157 (9th Cir.1996); Hilton Hotels Corp., 282 NLRB 819, 819, 821-22 (1987). For example, in one of these cases, the ALJ noted:
Hilton does not want to deal with any more unions at the Reno Hilton, or any other of its Nevada properties [including the Flamingo Hilton-Laughlin]. All agree that once [the Reno Hilton] learned of the union organizing activities, it decided at the highest corporate levels to oppose the Union and to involve all or most of its midlev-el and high executives in resisting the Union’s efforts.
Reno Hilton Resorts Corp., 319 NLRB at 1164; see also id. at 1164 n. 6; Hilton Hotels Corp., 282 NLRB at 821 (emphasizing evidence that the entertainment director for all of the Nevada properties was under “corporate instructions to fight” a unionization drive at the Reno Hilton). Indeed, in the past, management at Flamingo has even unlawfully refused to bargain with a union after it was elected and certified as the representative of a different bargaining unit at the hotel. See Flamingo Hilton-Laughlin, Inc., 306 NLRB No. 186, 140 L.R.R.M. (BNA) 1117 (Mar. 31, 1992), enforced, 19 F.3d 28 (9th Cir.1994).
In sum, the Board has clearly articulated the reasons why it concluded that the departure of several on-site supervisors has not substantially increased the possibility of a fair rerun election. In particular, contrary to the court’s suggestion, see opinion at 11, the Board has already addressed the significance of Sherlock’s resignation. Moreover, the Board cannot be faulted for failing to consider John Kosinski’s ‘departure because the record contains no evidence of this development.2 The court must defer to the Board’s “expert estimate as to the [continuing] effects on the election process of unfair labor practices,” NLRB v. Gissel Packing Co., 395 U.S. 575, 612 n. 32, 89 S.Ct. 1918, 23 L.Ed.2d 547 (1969); accord, Davis Supermarkets, Inc. v. NLRB, 2 F.3d 1162, 1175-76 (D.C.Cir.1993), so long as it has provided a reasoned explanation of its conclusions based upon substantial evidence in the record, see Ave-*1177cor, Inc. v. NLRB, 931 F.2d 924, 937-38 (D.C.Cir.1991).
I otherwise concur in the court’s opinion. The Board has not adequately explained why employee turnover had not ameliorated the effects of the hotel’s unfair labor practices to such an extent that a Gissel order was unnecessary. The Board dismissed the effects of employee turnover within the bargaining units primarily because the hotel’s “unlawful screening of job applicants ... continued for many months after the July 6,1993 election.” While the Board might well determine that an employer’s screening process, if used to alter natural employee turnover in order to disfavor the union in future elections, might leave “so lasting an imprint that a fair rerun election cannot be assured,” id. at 937, as the court makes clear, see opinion at 1172-1173, the Board’s assertion in this regard is not supported by the record. The ALJ only found that the hotel had screened out pro-Union applicants in the months directly preceding the election, and little evidence supports the conclusion that the screening continued afterwards. On remand the Board must “carefully consider employee turnover” and determine whether “changes in the [hotel’s] work force have made a bargaining order now inappropriate, even if one might have been appropriate at some earlier time.” Id. (quoting NLRB v. Pace Oldsmobile, Inc., 681 F.2d 99, 102 (2d Cir.1982) (per curiam)) (internal quotation marks omitted).
Although its finding that the hotel continued to screen out Union-leaning applicants after the election cannot be maintained, at least not without further explanation of the evidence and inferences on which it relies, the Board should consider on remand the fact that the hotel has not changed its hiring procedures and, thus, the potential for abuse remains. Prior to the election, the hotel modified its hiring practices by requiring a second approval step for job applicants. This additional level of review was used by supervisors in the hotel’s human resources department to disqualify applicants who had “friends or relatives working in the casino that were affiliated with the union.” Because this unlawful screening was carried out personally by one or two supervisors, it remained undetected until well into the course of the hearings before the ALJ. Although there is no evidence that the hotel’s human resources department is still using this second round of approval to dilute Union support, the procedure remains in effect. The ALJ noted that given the hotel’s “deep commitment” to resisting the unionization of its employees, “conduct this devious invites the presumption [that further tainting] could readily recur.” Somewhat undercutting this presumption, however, are the apparent facts that the supervisor responsible for devising and implementing the applicant screening, John Kosinski, is no longer employed by the hotel3 and that the responsibility for conducting the second approval step is now divided among several different members of the human resources department. These are considerations for the Board on remand.
Furthermore, aside from the issue of applicant screening, there may exist other reasons why substantial employee turnover within the bargaining units may have failed to dissipate the effects of Flamingo’s unfair labor practices. After cursorily dismissing the evidence of employee turnover as “irrelevant,” the ALJ remarked:
[T]here are several hundred employees remaining in the two units who experienced the influencing unfair labor practices. The facility never closes, and a more than ordinary potential is present for continuing and cross communication among new and longer service employees as well as conversation spanning departmental lines about many happenings of the Union’s long campaign.
This somewhat speculative conclusion does not, by itself, provide sufficient explanation for the imposition of the bargaining order. Cf. Be-Lo Stores v. NLRB, 126 F.3d 268, 283 (4th Cir.1997). The ALJ pointed to no evidence in the record that “cross-communication” had actually occurred but rather offered general assumptions that could equally *1178apply to many other employers. Perhaps realizing the inadequacy of these statements, the Board did not comment on them and instead chose to emphasize the hotel’s continued applicant screening as a factor undercutting the effects of substantial employee turnover. Nevertheless, on remand, the Board should reevaluate the ALJ’s findings and consider any evidence showing that knowledge of the hotel’s unfair labor practices continues to disseminate throughout the workforce. Laughlin, Nevada, is a relatively small population center whose chief industry consists of several large casino hotels, including the Flamingo. New employees, who have likely worked at other area casinos, may already know of the labor difficulties at the hotel and management’s determination to prevent unionization. But without specific findings by the Board supported by evidence in the record, such factors remain purely speculative and a bargaining order cannot issue. See Avecor, Inc., 931 F.2d at 938.
Finally, while the passage of time, in and of itself, should not be dispositive, see St. Francis Fed’n of Nurses & Health Prof'ls v. NLRB, 729 F.2d 844, 856 (D.C.Cir.1984); Peoples Gas Sys., Inc. v. NLRB, 629 F.2d 35, 47-48 (D.C.Cir.1980), it may increase the chances of a fair rerun election when combined with other changes in the bargaining unit, such as employee turnover. See J.L.M., Inc. v. NLRB, 31 F.3d 79, 84 (2d Cir.1994). Over five years have now elapsed since the tainted representation election. In its initial decision, the Board adopted the ALJ’s finding that the three-year lapse between the election and his order was representative of the normal course of litigation and particularly unavoidable due to the complexity of the instant case. Regardless of the adequacy of the Board’s reasoning, on remand the Board must readdress whether the intervening years, in conjunction with the changed circumstances, have helped to dissipate the remaining effects of Flamingo’s unfair labor practices. See Charlotte Amphitheater Corp., 82 F.3d at 1078; Avecor, Inc., 931 F.2d at 937.
. Before rendering his decision, the AO denied a motion by the hotel to reopen the record to admit evidence that three additional supervisors, including William J. Sherlock, the President of the hotel throughout the election period, had left its employ. The hotel has not raised any substantial challenge to this decision in its petition for review, and the court can only consider the evidence contained in the record. See 29 U.S.C. § 160(e),(f) (1994); Glomac Plastics, Inc. v. NLRB, 592 F.2d 94, 100 (2d Cir.1979). Nevertheless, the ALJ did consider the effect of Sherlock’s departure on the need for a bargaining order, and therefore the court can consider this evidence in reviewing the Board's order. See Charlotte Amphitheater Corp. v. NLRB, 82 F.3d 1074, 1080 (D.C.Cir.1996) (citing Conair Corp. v. NLRB, 721 F.2d 1355, 1388-89 n. 1 (D.C.Cir.1983) (Wald, J., dissenting)).
. In its briefs, the hotel asserts that Kosinski has left its employ, without specifying the date of his departure or offering any evidentiary support. From the record it is clear that Kosinski was still employed by the hotel throughout the course of the hearings before the ALJ. The Board also appeared to have no knowledge of his departure at the time it issued the bargaining order. There is no indication that the hotel ever alerted the Board to this factual development, and the Board had no obligation to inquire into Kosinski’s status. See Charlotte Amphitheater Corp., 82 F.3d at 1080.
. Although evidence of Kosinski's departure is not contained in the record, see supra note 2, on remand, the hotel may, of course, petition the Board to reopen the record to admit such evidence. See 29 C.F.R. § 102.48(b) (1998).