Earnings sharing in the U.S. Social Security system: a microsimulation analysis of future female retirees

The Growing Socioeconomic Gap in Lifetime Social Security Retirement Benefits: Current and Future Retirees

OBJECTIVES

Increasing socioeconomic disparities, including in life expectancy, have important implications for the US Social Security program. This study examined inter- and intra-cohort trends in Social Security retirement benefits, paying special attention to how lifetime benefit trajectories by socioeconomic circumstance shift across cohorts encompassing current and future retirees.

METHOD

Using a dynamic microsimulation model based on representative survey data linked to administrative records, we developed a set of cohort-specific projections that estimate monthly and lifetime Social Security retirement benefits for retirees spanning the Early Baby Boom (1945-1954) to Generation X (1965-1974) cohorts.

RESULTS

We found a widening socioeconomic gap in projected monthly and lifetime benefits for men and women, especially on a lifetime basis. This divergence is associated with stagnation of benefit levels among lower SES groups coupled with upward shifts among higher strata groups. Distributional changes are linked with increasing differential mortality, but other factors also likely play a role such as rising education premiums, growing earnings inequality, and changes in women's work and relationship histories.

DISCUSSION

Widening mortality differentials can lead to distributional changes in the US Social Security program. Microsimulation methodology lends insights into how the socioeconomic gap in monthly and lifetime benefit distributions may change among future older Americans in the context of differential mortality and other demographic changes. Moving forward in time, these complex patterns could offset some of the progressivity built into the system.

The Distributional Impact of Social Security Policy Options

Using microsimulation, we estimate the effects of three policy proposals that would alter Social Security's eligibility rules or benefit structure to reflect changes in women's labor force activity, marital patterns, and differential mortality among the aged. First, we estimate a set of options related to the duration of marriage required to receive divorced spouse and survivor benefits. Second, we estimate the effects of an earnings sharing proposal with survivor benefits, in which benefits are based entirely on earned benefits with spouses sharing their earnings during years of marriage. Third, we estimate the effects of adjusting benefits to reflect the increasing differential life expectancy by lifetime earnings. The results advance our understanding of the distributional effects of these alternative policy options on projected benefits and retirement income, including poverty and supplemental poverty status, of divorced and widowed women aged 60 or older in 2030.

Field of Study in College and Lifetime Earnings in the United States

Our understanding about the relationship between education and lifetime earnings often neglects differences by field of study. Utilizing data that matches respondents in the Survey of Income and Program Participation to their longitudinal earnings records based on administrative tax information, we investigate the trajectories of annual earnings following the same individuals over 20 years and then estimate the long-term effects of field of study on earnings for U.S. men and women. Our results provide new evidence revealing large lifetime earnings gaps across field of study. We show important differences in individuals' earnings trajectories across the different stages of the work-life by field of study. In addition, the gaps in 40-year (i.e., ages 20 to 59) median lifetime earnings among college graduates by field of study are larger, in many instances, than the median gap between high school graduates and college graduates overall. Significant variation is also found among graduate degree holders. Our results uncover important similarities and differences between men and women with regard to the long-term earnings differentials associated with field of study. In general, these findings underscore field of study as a critical dimension of horizontal stratification in educational attainment. Other implications of the empirical findings are also discussed.

Education and Lifetime Earnings in the United States

Differences in lifetime earnings by educational attainment have been of great research and policy interest. Although a large literature examines earnings differences by educational attainment, research on lifetime earnings--which refers to total accumulated earnings from entry into the labor market until retirement--remains limited because of the paucity of adequate data. Using data that match respondents in the Survey of Income and Program Participation to their longitudinal tax earnings as recorded by the Social Security Administration, we estimate the 50-year work career effects of education on lifetime earnings for men and women. By overcoming the purely synthetic cohort approach, our results provide a more realistic appraisal of actual patterns of lifetime earnings. Detailed estimates are provided for gross lifetime earnings by education; net lifetime earnings after controlling for covariates associated with the probability of obtaining a bachelor's degree; and the net present 50-year lifetime value of education at age 20. In addition, we provide estimates that include individuals with zero earnings and disability. We also assess the adequacy of the purely synthetic cohort approach, which uses age differences in earnings observed in cross-sectional surveys to approximate lifetime earnings. Overall, our results confirm the persistent positive effects of higher education on earnings over different stages of the work career and over a lifetime, but also reveal notably smaller net effects on lifetime earnings compared with previously reported estimates. We discuss the implications of these and other findings.