Projecting retirement income of future retirees with panel data: results from the modeling income in the near-term (MINT) project.

Cross-sectional data capture only a point in time and miss individual changes in earnings, labor force participation, marriage, fertility, and health. Because panel data follow individuals over time, they do not have this problem. The problems or concerns with cross-sectional data may be compounded when these data are used to make projections. Iams and Sandell (1997) found that using panel data on earnings explained much more variation in future earnings than using cross-sectional survey data. Panel data are also needed to estimate Social Security benefits, especially for women. Because of auxiliary benefits paid to spouses, ex-spouses, and widow(er)s of entitled workers, an individual's Social Security retirement benefit depends not only on his or her earnings history, but also on his or her marital history and the earnings histories of current and previous spouses. When we compare projected unreduced Social Security benefits with what they would be if we didn't have marital history or earnings history data for men, we find that: Benefits computed using only earnings histories are not very different from benefits computed using both earnings and marital histories. Benefits computed using only current earnings and marital histories underestimate benefits for those in earlier birth cohorts and overestimate benefits for those in the most recent birth cohort. Benefits computed without either marital or earnings histories underestimate benefits for all birth cohorts, but by much more for earlier cohorts than for more recent cohorts. For women we find that benefits computed without marital or earnings histories underestimate benefits in all birth cohorts. The largest differences are for women in earlier birth cohorts. Using both marital and earnings histories to estimate unreduced Social Security benefits, we find that men are projected to continue receiving higher benefits than women, although the gap is expected to narrow as the baby boomers near retirement age. We also look at the composition of projected total income available at retirement for those with incomes in the 45th-55th percentiles of the income distribution and find that: Total income at retirement is projected to be larger for men than for women in every birth cohort. Women are projected to receive the largest share of their total income from Social Security benefits. Men are projected to receive the largest share of their total income from other income sources, although this share declines as the baby boomers near retirement age.