Several factors must be evaluated to determine the savings to the Social Security Trust Fund of increasing the normal retirement age above 65. What was examined was the cost savings that could be attributed to raising the normal retirement age from 6 to 120 months above age 65 after adjusting for possible increases in disability incidence with age and for the higher mortality of disabled persons between ages 65 and 75. Other sets of potentially significant factors, not explicitly examined above, are labor-market conditions (that is, how many and what types of jobs are available for older workers), and psychological factor (that is, the motivation to continue gainful employment). The calculations show that, other things being equal, increases in disability prevalence between ages 65 and 75 will not substantially reduce the cost savings attributable to increasing the normal retirement age up to age 75. Thus, assuming that the U.S. labor market can absorb large numbers of older workers, and that older workers will be motivated to continue working, the savings generated by increases in normal retirement ages could be quite large. Indeed, with an increase of the normal retirement age of 70 or 72, it might be possible to provide much of the cost savings needed to meet the increased demands that will be put on the Social Security Trust Fund when the greatest number of the World War II baby boom cohorts reach age 65 in 32 years, in 2028. This savings may be possible because, in addition to the cost savings to the SSA pension program, the proportion of the population that continues to work until age 70 (or 72) will also contribute to the payroll tax. Their actual contribution will depend upon the numbers of older workers and their average wage rates. Nonetheless, the savings in pension costs (even adjusting for potential increases in disability with age), and the potential increases in payroll tax revenues, should significantly contribute to bringing the trust funds into actuarial balance.
为了确定将正常退休年龄提高到65岁以上能为社会保障信托基金节省多少资金，必须对几个因素进行评估。研究的内容是，在调整了因年龄增长导致的残疾发生率可能上升以及65岁至75岁之间残疾人较高的死亡率之后，将正常退休年龄从65岁以上提高6至120个月所能带来的成本节约。其他几组潜在的重要因素，上文未明确研究，包括劳动力市场状况（即老年工人可获得的工作数量和类型）以及心理因素（即继续从事有酬工作的动机）。计算结果表明，在其他条件相同的情况下，65岁至75岁之间残疾患病率的上升不会大幅减少将正常退休年龄提高到75岁所带来的成本节约。因此，假设美国劳动力市场能够吸纳大量老年工人，并且老年工人有继续工作的动机，提高正常退休年龄所产生的节约可能会相当可观。事实上，如果将正常退休年龄提高到70岁或72岁，当二战婴儿潮时期出生的最大一批人群在32年后的2028年达到65岁时，可能有可能提供满足社会保障信托基金增加的需求所需的大部分成本节约。这种节约之所以可能，是因为除了社会保障局养老金计划的成本节约外，继续工作到70岁（或72岁）的人口比例也将缴纳工资税。他们的实际贡献将取决于老年工人的数量及其平均工资率。尽管如此，养老金成本的节约（即使考虑到因年龄增长导致的残疾可能增加）以及工资税收入的潜在增加，应该会显著有助于使信托基金实现精算平衡。
