Similarly, a list of prices could have helped the union with accomplishing its stated goal of “compar[ing] the prices of competitors.” Not only was this information relevant to whether KLB faced an increasingly competitive business atmosphere, but the union's contemporaneously proffered reason for needing the information—double-checking the company's competitiveness claim—satisfies the “minimum standard of relevance” established by our precedent. New York and Presbyterian Hospital v. NLRB, 649 F.3d 723, 729 (D.C.Cir.2011). Of course, the specific information necessary to verify a competitiveness claim will vary depending on the circumstances of the case.
An employer's duty to bargain collectively under § 8(a)(5) of the NLRA includes the duty to supply a union with information that will allow it to "negotiate effectively and . . . perform properly its . . . duties as bargaining representative." N.Y. & Presbyterian Hosp. v. NLRB, 649 F.3d 723, 729 (D.C. Cir. 2011) (quotation omitted). Employers accordingly have a "general obligation . . . to provide information that is needed by the [union] for the proper performance of its duties."
A. Standard of Review This court reviews the Board's factual findings for substantial evidence, upholds the Board's application of law to facts “unless arbitrary or otherwise erroneous,” N.Y. & Presbyterian Hosp. v. NLRB, 649 F.3d 723, 729 (D.C.Cir.2011) (citations omitted) (internal quotation marks omitted), and gives “substantial deference” to inferences the Board draws from the facts, Halle Enters., Inc. v. NLRB, 247 F.3d 268, 271 (D.C.Cir.2001) (citation omitted) (internal quotation marks omitted). Furthermore, where “ ‘the statute is silent or ambiguous with respect to the specific issue, the question for the court is whether the [Board's] answer is based on a permissible construction of the statute.’ ”