in every age bracket. It is clear that many workers can continue in useful employment without harm to themselves, beyond age 65; to eliminate these on the basis of chronological age is socially wasteful. The large differences between elderly people also suggest that retirement based on evaluation of each worker's job performance and needs will in the aggregate be best from his standpoint.
However, if the question of retirement of elderly workers is to be considered on an individual basis, several factors other than the ability to continue working must be considered. The principal factors are: (a) the probable extra cost to health and longevity of continuing to face job stresses; (b) continued employment as a source of personal satisfaction; and (c) the question of whether financial and spiritual resources in retirement will be sufficient to meet personal needs for activity and health. At the present time data with respect to these factors are inadequate and criteria for judgment of their relative importance to individual workers are lacking. Therefore, for the elderly worker who is in good health the optimum time of retirement must be determined largely on an empirical basis.
We believe that the factors listed above are susceptible of investigation and analysis and that some useful criteria for determining when it would be best to retire would emerge from appropriate research. From the standpoint of the worker, the impact of job stress upon health may be the most important of the factors. Development of age norms of physiological and psychological functions together with sensitive tests to indicate "physiological age" of the individual in terms of these norms would make it possible to maintain personnel records of the rate of deterioration and current status of individual employees in their later years. The far more subtle but equally important factors of individual satisfaction and personal needs associated with work and retirement can not be assessed fully except through longitudinal studies of elderly persons, both those who have, and those who have not, retired. The results of such investigations might then form the basis for a preparatory program of consulting and education, to be started several years before a decision about retirement is faced.
Because of the dearth of information on these factors we do not