The U.S. Supreme Court case Pittsburgh Plate Glass Co. v. National Labor Relations Board in 1940 revolved around the issue of collective bargaining and labor rights within a company's pension plan for employees. The Pittsburgh Plate Glass Company was accused by the National Labor Relations Board (NLRB) of violating the Wagner Act, which protects workers' rights to organize and collectively bargain with their employers, by refusing to negotiate changes in its retirement plan with a union representing some of its employees. The company argued that it had no obligation under federal law to discuss these matters as they were not part of "conditions of employment." However, NLRB insisted that pensions fell under this category and should be subject to negotiation between employer and employee representatives. The Supreme Court ruled in favor of the Pittsburgh Plate Glass Company stating that an employer is not required by federal law to negotiate over issues related to retirement benefits if those benefits are derived from an existing trust fund managed independently from the company’s control or influence because such funds do not constitute wages or conditions directly tied up with employment.

In the dissenting opinion for Pittsburgh Plate Glass Co. v. National Labor Relations Board, Justice Frankfurter argued that the majority's decision was a departure from established principles of labor law and policy. He contended that employees have a legitimate interest in knowing about their employer's financial condition, particularly when it is used as justification for wage cuts or other adverse employment actions. The majority's ruling, he believed, undermined collective bargaining by denying workers access to information necessary to negotiate effectively with their employers. Furthermore, he disagreed with the majority’s interpretation of “collective bargaining” under Section 8(5) of the National Labor Relations Act (NLRA), asserting that it should be construed broadly to include discussions on wages and working conditions rather than narrowly limited to contractual negotiations only.