Pеtitioners and cross-respondents, Providence Hospital and Mercy Hospital (collectively, the Hospitals), seek judicial review of an adverse administrative determination. We deny the petition and enforce the order of respondent and cross-petitioner, the National Labor Relations Board (the Board).
I. BACKGROUND
The Hospitals are members of the Sisters of Providence Health System (SPHS), a chain of not-for-profit institutions operating in western Massachusetts. The Hospitals’ nursing staffs are unionized and the Massachusetts Nurses Association (MNA) represents the nurses. Spurred by rumors of an impending consolidation, an MNA representative, Shirley Astle, wrote to the president of Mercy Hospital on August 11, 1993, requesting relevant particulars. The hospital responded that it was too early to predict the changes that might result from a consolidation, and that in all events a reduction in force would likely be restricted to management personnel.
Shortly thereafter SPHS announced plans to consolidate the Hospitals’ administrations. As the first step in the pavane, it appointed Vincent McCorkle as president and chief executive officer of both institutions. A letter dated September 28, 1993, sent to the union by a member of the newly unified management team, confirmed the earlier assurance that, although management would be “look[ing] at ways to integrate how [the Hospitals] provide care,” there were no definite plans to downsize the bargaining units. It was simply “too early to determine the nature and extent of any potential impact on employee working conditions.”
On February 24, 1994, McCorkle sent a letter to the Hospitals’ combined work force. The letter informed the employees of a perceived “need to adjust ... staffing levels” and suggested that this adjustment would be accomplished at least in part by reduction in force. 1 Roughly three weeks thereafter the *1015 Hospitals advised local media outlets that some 200 positions would be eliminated as part of the ongoing consolidation. A second press release, distributed later that same week, indicated that despite management’s earlier assurances 198 Mercy Hospital employees and six Providence Hospital employees had been cashiered. 2
On the very day that McCorkle first announced the impending reduction in force, SPHS and a competing health-care system, Holyoke-Chieopee Area Health Resources (HCAHR), signed a memorandum of understanding (MOU) commemorating their intent to merge. McCorkle informed the Hospitals’ employees of the plannеd merger on February 25,1994. Although this statement hinted at a further reorganization and possible future efficiencies of scale, McCorkle claimed that no decisions had been made regarding future staffing. In short order, SPHS and HCAHR submitted applications to federal and state agencies in an endeavor to gain necessary regulatory approvals.
On May 5, 1994 — with layoffs a reality and with a merger now in the offing — Astle requested a copy of SPHS’s “business plan,” saying that the MNA wanted “to begin its assessment of the merger’s impact on the conditions of work for the RNs MNA represents at Providence and Mercy Hospitals.” McCorkle temporized while forwarding the rеquest to counsel. Astle wrote again on May 24, complaining that she had received no substantive response. The Hospitals’ lawyer finally replied on June 2, but he gave MNA’s request the back of his hand; the attorney took the position that SPHS “is a totally separate corporation,” and, therefore, the Hospitals did not have access to a copy of the desired document (if, indeed, such a document existed).
MNA chose not to quibble. Instead, it renewed its request in somewhat altered form. In letters dated July 26 and August 5, respectively, it set forth a particularized listing of documents that it wished to examine, a detailed statement of the reasons underlying its information requests, and the legal basis upon which the requests rested. 3 Regarding the internal consolidation, MNA asked that the Hospitals provide copies of (1) all documents relating to the consolidation (or in lieu thereof, a detailed explanation of the consolidation); (2) any plans for further work force reductions at Mercy Hospital; and (3) any plans regarding changes in the Hospitals’ corporate status. As to the anticipated merger with HCAHR, MNA sought (1) copies of the MOU and other documents explicating the merger’s terms; (2) plans for, or information about, proposed staffing changes at Mercy Hоspital in consequence of this merger; and (3) all documents pertaining to the Hospitals’ proposed corporate status within the merged group of facilities. Each request solicited a response within ten days.
The Hospitals asserted that they needed additional time to formulate a meaningful response. MNA waited patiently for more than a month before sending a follow-up letter on September 12. Receiving no immediate response, the union then filed charges with the Board. As the Board’s processing of the charging papers drew to a close, the Hospitals provided MNA with some — but not all — of the requested data, characterizing their December 29 transmittal as a “response to the NLRB information charge.” The Board’s regional director issued a formal complaint ten days later. In May 1995 — on the eve of the NLRB hearing' — the Hospitals supplied MNA with materials explaining their corporate structure and reaffirming that no further layoffs would result from the internal consolidation. They furnished no *1016 data relating to the proposed merger with HCAHR.
The matter was heard by an administrative law judge (ALJ) who took evidence and reserved judgment. Three months elapsed before the ALJ issued his decision. In the interim HCAHR purported to terminate the MOU. Displeased no little and quite some, SPHS filed suit in state court alleging breaсh of the MOU and seeking, inter alia, specific performance.
II. THE BOARD’S DECISION
In September 1995 the ALJ published his findings and a proposed order. He determined that the Hospitals had breached their duty to bargain in good faith by withholding information relevant to the performance of the union’s undertakings as a collective bargaining representative, and had thereby violated the National Labor Relations Act (NLRA), specifically, 29 U.S.C. § 158(a)(1) & (5).
The Hospitals took exception to the decision and appealed to the Board. The Board adopted the ALJ’s findings and rationale,
4
albeit modifying the recommended order slightly.
See Providence Hosp.,
320 N.L.R.B. No. 60,
The Board first addressed MNA’s requests for information regarding the internal consolidation. It adjudged this information relevant because MNA might well have needed it “so that it could determine what legal effect if any [the consolidation] would have on its collective-bargaining agreements with the hospitals, when it should demand bargaining over the effects of the transaction,” and what effect the restructuring would have on the bargaining units. See id. at *7. Turning to the requests regarding the proposed merger, the Board found that information to be relevant, even though not directly linked to terms and conditions of employment. See id. at *8. It explained that “MNA needed to know the impact of the proposed [merger] on its contracts,” as well as any other possible effects on the status of the bargaining units. Id. at *9. Moreover, MeCorkle’s letters to the employees suggested the possibility “that some decisions might have been made which would affect bargaining unit employees.” Id.
III. DISCUSSION
We start by reiterating the deferential standard that obtains when federal courts review orders of the Board. Then, before moving to specifics, we discuss in general terms the scope of an employer’s duty to disclose relevant information to an inquiring union.
A The Standard of Review.
When a party challenges the Board’s determination that it has committed an unfair labor practice, an inquiring court must sсrutinize the record as a whole. As to matters of fact, the court should uphold the Board’s findings if they are supported by substantial evidence.
See Universal Camera Corp. v. NLRB,
B. The Duty to Disclose.
The NLRA imposes upon employers and unions alike a duty to bargain in good faith over “wages, hours, and other terms and conditions of employment.” 29 U.S.C. § 158(d). The right to bargain collectively would be little more than a hollow promise if a bargaining representative did not have the
*1017
concomitant right to muster the information needed to conduct that bargaining effectively. Thus, “[t]he duty to bargain collectively ... includes a duty to provide relevant information needed by a labor union for the proper performance of its duties as the employees’ bargaining representative.”
Detroit Edison Co. v. NLRB,
Stating the rule is not a surefire means of dispelling all uncertainty. Relevance, like beauty, sometimes lies in the eye of the beholder, and parties can differ about what information is (or is not) relevant to a union’s functions
qua
bargaining agent. Stated in traditional terms, requested information is relevant if it seems probable that the information will be of legitimate use to the union in carrying out its duties and responsibilities
qua
bargaining agent.
See NLRB v. Acme Indus. Co.,
The Board and the courts have put a gloss on the test for relevancy—a gloss that alters the burden of persuasion depending upon the nature of the data sought by the union. When “the requested information concerns wages and related information for employees in the bargaining unit, the information is presumptively relevant to bargaina-ble issues.”
Soule Glass & Glazing Co. v. NLRB,
Once the
Board has made its assessment of whether particular information must be produced, the standard of review looms large. At that juncture, a reviewing court should accord considerable respect both to the Board’s determination and to the factual findings underpinning it.
See NLRB v. New England Newspapers, Inc.,
C. The Merits.
It is against this backdrop that we mull the assignments of error. The Hospitals interpose both relevancy and confidentiality objections to the Board’s decision concerning the requests for merger-related information. They lodge relevancy and substantial compliance objections to the Board’s decision concerning the requests for consolidation-related information. Finally, they question the scope of the Board’s order. Although the applicable legal рrinciples overlap, we treat these five points separately.
*1018 1. Relevance of the Planned Merger. The Hospitals’ relevancy objection to the compulsory sharing of merger-related information is painted with too broad a brush. Whatever generalities may pertain to proposed mergers in the abstract, the concrete (and somewhat unusual) factual circumstances surrounding this proposed merger afford substantial evidence adequate to support the Board’s order.
To be sure, certain management actions that ultimately may have a significant impact on the terms and conditions of employment within the bargaining unit are nonetheless beyond the purview of collective bargaining. In a much-quoted turn of phrase, Justice Stewart referred to these actions as comprising “the core of entrepreneurial control.”
Fibreboard Paper Prods. Corp. v. NLRB,
Although the content of this core of entrepreneurial control eludes a precise description, see
United Food & Commercial Workers, Etc. v. NLRB,
Still, there is an important distinction between the right to bargain about a core entrepreneurial business decision (a right which a union does not possess) and the right to bargain about the effects of that decision on employees within a bargaining unit (a right which, depending upon the overall circumstances, a union may possess). After all, subject to considerations such as relevancy and immediacy, unions generally enjoy the right to bargain over the effects of decisions which are not themselves mandatory subjects of collective bargaining.
See First National Maint.,
In an effort to parry the union’s thrust, the Hospitals offer two reasons why MNA could not properly predicate these information requests on a desire to engage in effects bar *1019 gaining. They suggest that (1) such bargaining always must await the culmination of a pending merger (and here, the parties have not finalizеd the transaction and may never do so), and (2) even if a pending merger can sometimes be an appropriate subject of effects bargaining, the prospects of this particular merger are too dim and its outline too amorphous to warrant a finding of relevancy (especially since restraint-of-trade laws may limit any detailed discussions of operating efficiencies until the merger is consummated). In our view, neither suggestion is convincing.
The Hospitals’ contention that effects bargaining (or, more accurately, the gathering of information preliminary to effects bargaining) always must await the consummation of а merger depends almost entirely on their reading of our decision in
Northeast Airlines.
That decision however, is incapable of carrying the cargo that the Hospitals load on it. For one thing, the question that we discussed in
Northeast Airlines
arose in a materially different legal posture. There we affirmed the district court’s denial of an injunction sought by a union as a means of preventing the merger of the employer into an independent company.
See Northeast Airlines,
This brings us to the Hospitals’ second argument. It is common ground that a union cannot demand bargaining over effects that are purely speculative, ephemeral, or too far removed from the underlying activity.
See Detroit Edison,
A union is entitled to plan in advance for likely contingencies. Under the totality of the circumstances that existed here—especially the employer’s expressed confidence that the merger would take place soon and the emphasis in its handouts on the reallocation of personnel—we believe it was within the Board’s authority to find that the union’s professed need for specifics about the merger’s probable impact on the bargaining unit was reasonable.
See Union Builders, Inc. v. NLRB,
We add an esehotocol of sorts. The Hospitals claim that the ultimate failure of the merger
8
takes two bites out of the Board’s case, serving not only to moot the information requests but also to underscore their prematurity. We are not persuaded. The relevance of requested information must be determined by the circumstances that exist at the time the union makes the request, not by the circumstances that obtain at the time an agency or a court finally vindicates the union’s right to divulgement.
See NLRB v. Arkansas Rice Growers Coop. Ass’n,
2.
Confidentiality.
The Hospitals’ second line of defense is that the MOU was subject to a side agreement requiring the parties to keep all matters pertaining to the merger secret. We agree with the basic premise on which this defense rests: an employer’s commitment to, or genuine need for, confidentiality sometimes can constitute an appropriate reason for keeping documents— even documents that are potentially relevant to the collective bargaining process—out of a union’s hands.
See Detroit Edison,
But there is less here than meets the eye. Because confidentiality is in the nature of an affirmative defense, it is the employer’s burden to demonstrate thаt the requested information is shielded by a legitimate privacy claim.
See Mary Thompson Hosp. v. NLRB,
Setting this principle into motion, the Board has held that it is untimely for an employer to raise a confidentiality objection
*1021
to an information request for the first time after proceedings before the Board have been commenced.
See Detroit Newspaper Agency,
3. Relevance of the Internal Consolidation. The Board also found that MNA’s requests for information regarding the consolidation were relevant. This finding cаnnot seriously be questioned.
MNA initially sought this information in the summer of 1993. It honed'the information requests and renewed them several times in the succeeding months. Aside from broad denials that the consolidation would have any effect on the bargaining units, management’s first substantive response came late in 1994 (after MNA had preferred charges and the Board was on the verge of issuing a complaint). In the intervening fifteen months (during which interval MNA made five separate requests for information about the consolidation) the Hospitals laid off more than 200 workers. In light of the continuing uncertainty about imminent corporate restructuring — uncertainty fed by statements attributаble to management— MNA reasonably could have believed that further changes were in the offing. Consequently, the Board plausibly could have found- — as it did — that the requested information had great importance to the union and was, therefore, relevant. This is especially so in view of the fact that the collective bargaining agreement at Providence Hospital expired on December 31, 1994, unless automatically renewed, and MNA had to decide no later than October 1, 1994 whether to allow the contract to renew automatically or to reopen negotiations.
The Hospitals offer no convincing rebuttal tо the Board’s relevancy finding. As the Board noted,
see Providence Hosp.,
4.
Substantial Compliance.
We dismiss out of hand the Hospitals’ suggestion that their belated disclosure of consolidation-related information cures their default. MNA made a series of information requests over a period spanning thirteen months. The Hospitals stonewalled for that entire length of time. They then furnished some information in December of 1994 (aftеr the Board investigation had begun) and some in May of 1995 (on the eve of the hearing). Even assuming
arguendo
that the two batches of belatedly supplied information in the aggregate fulfilled the union’s requests, the
*1022
Hospitals’ act of contrition came too late. As the Board explained, the protracted delay that separated the requests from the divulgement of data could “not be attributed to the time needed to assemble the information furnished.”
Id.
at *8. A union is entitled to timely disclosure of relevant information. See
Capitol Steel & Iron Co. v. NLRB,
5.
The Scope of the Order.
We briefly touch upon the Hospitals’ objection to the Board’s remedial order. Some background is desirable. The ALJ initially recommended that the Hospitals be required to furnish “in a timely fashion, on request, information concerning any proposed affiliation or consolidation of Mercy Hospital and Providence Hospitals with one another and concerning proposed mergers, consolidations, or affiliations of Providence and Mercy Hospitals with other health care providers.”
See Providence Hosp.,
The modified order responds to the reality that, here, an unusual concatenation of events exist, e.g., the Hospitals’ presentation of the merger as a done deal, their insistence that the MOU obligated the signing parties even after HCAHR had repudiated it, and their stоnewalling in the face of repeated information requests. What is more, by specifying the information that the Hospitals must disclose, the Board limits the remedy and leaves future transactions untouched. This step fits neatly with our belief that each situation is sui generis, and that pending mergers may or may not be a proper subject of effects bargaining (depending on the individualized circumstances). Based on these considerations, the modification falls well within the Board’s province.
IV. CONCLUSION
We need go no further. For the reasons elucidated above, we hold that the Board’s decision and order comport with applicable precedent and are supported by substantial evidence in the record.
The petition for review is denied. The cross-petition for enforcement is granted. Costs will be taxed in favor of the Board.
Notes
. The communique added that the Hospitals had intended to delay informing workers about these *1015 layoffs until plans crystallized, but that a threatened news leak forced management's hand.
. The record indicates that thirty-eight of the individuals laid off at Mercy were nurses. The record is silent, however, as to whether any nurses were laid off at Providence.
. Sandwiched between these requests was a letter from McCorkle to the Hospitals’ employees offering insights anent the proposed merger. In this missive, dated July 29, 1994, McCorkle acknowledged that some departments would be amalgamated but predicted that “most jobs will be saved and moved within the new system.” An attachment hinted at possible future reductions in force (though claiming that "right now, we have no game plan for layoffs”).
. The Board is not obliged to make independent findings or conduct its own analysis of the factors prompting an order where, as here, it expressly adopts the ALJ's findings and reasoning.
See NLRB v. Horizon Air Servs., Inc.,
. The standard is analogous to the relevancy standard that governs in the pretrial discovery process, under which discovery initiatives are deemеd relevant as long as they seem calculated to lead to the unearthing of admissible evidence.
See Acme Indus.,
. We think that mergers involving independent entities are to be distinguished from internal consolidations involving a combination or realignment of subsidiaries owned by a common parent. Such internal consolidations do not require the same degree of “secrecy, flexibility and quickness” that, according to
Northeast Airlines,
. Another difference—but one to which we attach little weight—is that
Northeast Airlines
involved the Railway Labor Act (RLA), 45 U.S.C. §§ 151-188. We deem it settled that cases brought under the RLA can inform the decisional process under the NLRA.
See, e.g., Trans World Airlines v. Independent Fed. of Flight Attendants,
. In candor, it is far from clear that the merger is a dead letter. SPHS’s suit against HCAHR is still pending in the state court. In its complaint SPHS terms the MOU "binding” and asks for specific performance.
. The Hospitals’ asseveration that they could not explain the need for confidentiality without revealing privileged information proves too much. If that was the case, then the Hospitals were obliged to cite that dilemma in response to the MNA's requests. They did not do so.
. We reject the Hospitals’ contention that public availability of the requested information obviated the need for disclosure. The argument is inherently circular: MNA could not possibly know that all the information was in the public domain' if the Hospitals refused to turn over the requested documents or to make any other substantive response. At the very least, the Hospitals had the duty to explain to MNA in a timely fashion that everything was out in the open. As the Board put it, “the Union was entitled to hear that [news] directly from the [Hospitals].” Providence Hosp., 1996 WL 48263, at *8.
