of employee and the employing entity (usually a corporation, but occasionally a human being). A "contract" is an agreement enforceable in law. Very often it can be written down, or signed, but an oral agreement is also a fully enforceable contract. Because employees have unequal bargaining power compared to almost all employing entities, most employment contracts are "standard form". Most terms and conditions are photocopied or reproduced for many people. Genuine negotiation is rare, unlike in commercial transactions between two business corporations. This has been the main justification for enactment of rights in federal and state law. The federal right to collective bargaining, by a labor union elected by its employees, is meant to reduce the inherently unequal bargaining power of individuals against organizations to make collective agreements. The federal right to a minimum wage, and increased overtime pay for working over 40 hours a week, was designed to ensure a "minimum standard of living necessary for health, efficiency, and general well-being of workers", even when a person could not get a high enough wage by individual bargaining. These and other rights, including family leave, rights against discrimination, or basic job security standards, were designed by the United States Congress and state legislatures to replace individual contract provisions. Statutory rights override even an express written term of a contract, usually unless the contract is more beneficial to an employee. Some federal statutes also envisage that state law rights can improve upon minimum rights. For example, the Fair Labor Standards Act of 1938 entitles states and municipalities to set minimum wages beyond the federal minimum. By contrast, other statutes such as the National Labor Relations Act of 1935, the Occupational Safety and Health Act of 1970, and the Employee Retirement Income Security Act of 1974, have been interpreted in a series of contentious judgments by the US Supreme Court to "preempt" state law enactments. These interpretations have had the effect to "stay experimentation in things social and economic" and stop states wanting to "serve as a laboratory" by improving labor rights. Where minimum rights do not exist in federal or state statutes, principles of contract law, and potentially torts, will apply. Aside from terms in oral or written agreements, terms can be incorporated by reference. Two main sources are collective agreements and company handbooks. In JI Case Co v National Labor Relations Board an employing corporation argued it should not have