(dissenting):

I respectfully dissent. I agree with the majority that the Board’s adjudication of this dispute was not entirely satisfactory because the Board failed to articulate the basis for its conclusion that the contract-bar rule does not apply here. Unlike the majority, however, I would not draw the inferences necessary to support the Board’s decision. Rather, I would remand the matter to the Board for an explanation of the basis of its decision not to apply the contract-bar rule.

As the majority correctly points out, the Board’s longstanding interpretation of the contract-bar rule does not square precisely with the Board’s most recent contract-bar decision, American Sunroof Corp.-West Coast, Inc., 243 NLRB No. 172 (1979). Up until the American Sunroof decision, it appeared that a valid disclaimer of representational interest by a union was insufficient, standing alone, to suspend the contract-bar rule. Instead, under the formulation set forth in East Manufacturing Corp., 242 NLRB No. 5 (1979), a valid disclaimer merely prompted the Board to examine the policies underlying the rule. In deciding whether to impose a contract bar, the Board would strike a balance between the need to preserve industrial stability and the need to protect the employees’ right to a reasonable opportunity to change their bargaining representative. Balancing these important policy considerations was paramount in deciding whether to direct an election or to enforce the contract-bar rule.

In American Sunroof, however, the Board appeared to adopt, implicitly, a new interpretation of the contract-bar rule. In American Sunroof, without balancing the two competing policies, the Board suspended the contract-bar rule because of a valid disclaimer of interest by an incumbent union. Thus the current effectiveness of the contract-bar rule is questionable.

The majority opinion does not dispel this uncertainty. The majority succinctly states the policies relevant under pre-American Sunroof decisional law and endorses their consideration by the Board. Yet the majority then appears to validate the suspension of the contract-bar rule on the sole ground that Local 49’s disclaimer was valid. I am uncertain whether the majority is deciding that a valid disclaimer alone effectively suspends the contract-bar rule or whether the competing policies must still be considered. To avoid creating further confusion, I would grant the Board an opportunity to clarify its position. We have in the past recognized and deferred to the Board’s expertise in these matters before rendering an opinion and I see no reason to depart from that policy now.

Generally we do not substitute our rationale for the rationale provided by the Board in its decisions. FTC v. Sperry & Hutchison Co., 405 U.S. 233, 249-50 , 92 S.Ct. 898, 907-08 , 31 L.Ed.2d 170 (1972); Bob’s Big Boy Family Restaurants v. NLRB, 625 F.2d 850 (9th Cir. 1980). Because the Board did not explain its decision to suspend the contract-bar rule, I think it appropriate to remand the matter to afford the Board an opportunity to explain the underlying rationale of its decision.