The Health and Retirement Study (HRS) is a long-running study that examines middle-aged and older adults in the US, producing data that is used both domestically and internationally. As a panel survey, HRS follows approximately 20,000 U.S. adults, some of whom have participated in the study for 30 years, through the retirement and aging process.

Founded in 1968, the Panel Study of Income Dynamics PSID is the world’s longest-running household panel survey. It has made way for the study of dynamism in social and behavioral processes, resulting in over 4,000 peer-reviewed publications. The National Science Foundation, the study’s lead sponsor, named PSID as one of its 60 most significant innovations.