After giving an overview of the private retirement system and considering deferred wages and labor costs, the study explores the extent of the influence of private pensions on early retirement and on job opportunities of older persons, and the influence of lengthy job tenure requirements on worker mobility. The study weakens the case for across-the-board increases in social security benefits based on old formulas for computing base level benefits by which social security will become an increasingly inefficient instrument for putting money in the hands of the poor or near-poor aged. The fact that a large share of workers are likely to remain uncovered by private pensions strengthens the case for splitting social security's pension function from its antipoverty function. Present formulas attempt to provide the most generous treatment to those who contributed least; as private pensions grow, this policy may yield increasingly haphazard results. Finally, some of the findings demonstrate how unfair the social security retirement test is, making difficult the attempt of the aged worker without a private pension to use earnings to supplement his social security benefits. (Author/AJ)