In Allied Chemical & Alkali Workers of America v. P. P. G. Co. (1971) 404 U.S. 157, the United States Supreme Court reversed a decision by the National Labor Relations Board declaring that the employer's unilateral alteration of pension benefits for retired employees violated the NLRA requirement to bargain over the terms and conditions of employment. The court explained that the requirement to bargain with a union over wages, hours and working conditions "extends only to the 'terms and conditions of employment' of the employer's 'employees' in the 'unit appropriate for such purposes' that the union represents." (Id. at p. 164 30 L. Ed. 2d at p. 349.) The court further concluded that pension benefits for retired workers does not "vitally affect" the terms and conditions of employment of active employees within the bargaining unit. (Id. at p. 182 30 L. Ed. 2d at p. 359.)