Length of service as a criterion governing personnel decisions is a widely applied normative principle. Contractual agreements that provide that employees' status with respect to promotion and layoff be based on seniority serve to limit discrimination and favoritism, remove an element of competition among workers, and provide a form of social insurance against the contingencies of aging. This status variable is sometimes erroneously perceived as “job ownership.” Decline of labor turnover, the aging of the labor force, and growth of pension programs reinforce concern about seniority. Expectations based on seniority have been challenged under the Civil Rights Act by former discriminatees who question the fairness of the rank ordering. In times of declining opportunity seniority as an allocative device assumes greater importance, while in a utopia, where all jobs are equally satisfying and there is full employment, seniority would be irrelev