We used data from the Panel Study of Income Dynamics (PSID), which is the longest-running nationally representative household survey in the world. It began in 1968 with interviews of 4802 families in the United States that included 18230 individuals of all ages. The PSID included an oversample of low-income and Black families so that issues of poverty and race could be examined. Sample weights account for oversampling and make the weighted sample nationally representative, and these weights are used in all analyses. PSID families and their descendents were reinterviewed each year through 1997, when interviewing became biennial.