The National Labor Relations Act (NLRA) requires businesses to bargain in good faith with their employees’' labor unions and prohibits the use of unfair labor practices directed against employees and unions seeking to organize them. 29 U.S.C. § 151 et seq. Large, dominant enterprises often use contingent workers to insulate themselves from liability and the obligation to bargain collectively. Congress gave the NLRA the restrictive common-law definition of employment relationships and rejected the Supreme Court’'s early effort to apply a broader definition. See NLRB v. United Ins. Co., 390 U.S. 254 (1968). The National Labor Relations Board (NLRB), which is owed deference by the courts in interpreting and enforcing the NLRA, has developed its own method of implementing the common law standard.. Is the Worker an “"Employee”" or “"Independent Contractor”"? Where a worker is not an “"employee,”" the relationship between the worker and the company is considered a commercial one between a company and an independent contractor. The NLRA has applied the common law standard to determine alleged independent contractor status, not always consistently, in such cases as Roadway Package System, 326 NLRB No. 72 (NLRB found delivery drivers to be employees); Dial-A-Mattress, 326 NLRB No. 75 (1998)(NLRB found delivery drivers to be independent contractors). The Single Employer Theory: Two Businesses Acting as One. One way to overcome the obstacles created by a contracting relationship is to show that the dominant enterprise and its contractor are in reality a single employer. This is possible in exceptional circumstances where the two are extremely closely related and integrated. The Board looks at four factors, none of which alone is controlling: common ownership, common management, interrelationships in operations, and common control of labor relations. Dow Chemical Co., 326 NLRB No. 23 (1998). The NLRB looks to actual, not potential, control, and the potential control of parent corporations over subsidiaries is not alone sufficient. Where a single employer is shown, employees of the contractor have full protection of the NLRA with respect to the dominant enterprise and the contracting company.