PROJECT ABSTRACT Prior studies have reported that the Medicare program does not result in significant declines of mortality rates, except among severely ill patients who require immediate hospitalization and among the disabled. But none of the previous studies has estimated the lifetime effects of having access to the Medicare program—they only investigated its short-term impacts. In other contexts, prior research has found that short-term evaluations can miss important long-term effects. In the case of policies affecting health care access, this issue is particularly important. Because Medicare covers important preventive care and helps participants to manage chronic conditions, the cumulative impact of having access to Medicare might be big, even if its short-term impact is limited. The main goal of this project is to estimate the long-term impact of Medicare on longevity for the population as a whole and various subgroups. Prior work is often limited in its investigation of heterogeneity because it relies on published aggregate mortality rates which are only broken down by geography, gender, race/ethnicity, and age, but not by any other measure of socioeconomic status. Thus, a knowledge gap exists on the lifetime effect of Medicare on individual (completed) longevity and whether this varies across socioeconomic groups. The proposed exploratory project will examine the impact of Medicare’s introduction on the longevity of the affected cohorts. When Medicare took effect in July 1966, it created variations in the age when Medicare’s first-generation recipients gained Medicare coverage: for example, those born in 1902 became eligible at 65 whereas those born in 1891 gained eligibility at age 75. This project will use a large and newly created dataset that links the US census with genealogical data. To our knowledge, this dataset will be the largest dataset to date in the US containing information on both individual longevity as well as individual socioeconomic characteristics. This study will first examine Medicare’s short-term effects on annual mortality rates, reevaluating previous studies but using individual-level data, and extending the results to look at effects among various subgroups (Aim 1). Then, this project will investigate the cumulative long-term effect of Medicare on longevity by comparing the average longevity of individuals who gained Medicare at different ages using an interrupted time-series analysis, for all and by subgroup (Aim 2). Finally, the project will leverage geographic and individual variation in private health insurance before Medicare’s introduction to estimate the causal lifetime effect of Medicare on longevity (Aim 3). A difference-in-differences strategy will be used: we will assess if the changes in longevity for groups who gained Medicare coverage at age 65 or at older ages are greater for those who were already likely to have private health insurance, either because of their geographic location or their personal characteristics. The analysis will be repeated based on occupation, education, income, and other measures of socioeconomic status.

PROJECT NARRATIVE Little is known about the lifetime effect of Medicare on individual longevity and whether it varies across socioeconomic groups. The impact of Medicare’s introduction on completed longevity will be evaluated using new data and a novel empirical approach. Results from this study will contribute to scientific knowledge that will inform the design of health insurance programs in the US.