At-will employment is a doctrine of American law that defines an employment relationship in which either party can break the relationship with no liability, provided there was no express contract for a definite term governing the employment relationship and that the employer does not belong to a collective bargaining group (i.e., has not recognized a union). Under this legal doctrine:
Several statutory and judge-made exceptions to the doctrine exist, especially if unlawful discrimination is involved regarding the termination of an employee. These restrictions have been controversial; an empirical study in 1992 by the RAND Corporation showed that imposing exceptions to at-will employment resulted in a long-term drop in aggregate employment of two to five percent.