factors of traditional common law tests may not be replaced if a statute gives no further definition of "employee" (as is usual, e.g., the Fair Labor Standards Act of 1938, Employee Retirement Income Security Act of 1974, Family and Medical Leave Act of 1993). Alongside the purpose of labor legislation to mitigate inequality of bargaining power and redress the economic reality of a worker's position, the multiple factors found in the Restatement of Agency must be considered, though none is necessarily decisive. Common law agency tests of who is an "employee" take account of an employer's control, if the employee is in a distinct business, degree of direction, skill, who supplies tools, length of employment, method of payment, the regular business of the employer, what the parties believe, and whether the employer has a business. Some statutes also make specific exclusions that reflect the common law, such as for independent contractors, and others make additional exceptions. In particular, the National Labor Relations Act of 1935 §2(11) exempts supervisors with "authority, in the interest of the employer", to exercise discretion over other employees' jobs and terms. This was originally a narrow exception. Controversially, in NLRB v Yeshiva University, a 5 to 4 majority of the Supreme Court held that full time professors in a university were excluded from collective bargaining rights, on the theory that they exercised "managerial" discretion in academic matters. The dissenting judges pointed out that management was actually in the hands of university administration, not professors. In NLRB v Kentucky River Community Care Inc, the Supreme Court held, again 5 to 4, that six registered nurses who exercised supervisory status over others fell into the "professional" exemption. Stevens J, for the dissent, argued that if "the 'supervisor' is construed too broadly", without regard to the Act's purpose, protection "is effectively nullified". Similarly, under the Fair Labor Standards Act of 1938, in Christopher v SmithKline Beecham Corp, the Supreme Court held 5 to 4 that a traveling medical salesman for GSK of four years was an "outside salesman", and so could not claim overtime. People working unlawfully are often regarded as covered, so as not to encourage employers to exploit vulnerable employees. For instance in Lemmerman v AT Williams Oil Co, under the North Carolina Workers' Compensation Act an eight-year-old boy was protected as an employee, even though children working under the age of 8 was unlawful. However, in