Creating economic opportunities for all?regardless of class, sex, and race or ethnic origin?is fundamental to maintaining economic growth and a functioning democracy. This ideal was the bedrock of U.S. policies that made the U.S. an international leader in education in the late-19th and mid-20th century, giving rise to one of the most literate and educated and equal (in terms of wages) populations in the world (Goldin and Katz 2010, Goldin and Margo 1992).
In the last 50 years, income (and wealth) inequality in the U.S. have soared to their highest levels since 1917. Influential recent work using administrative tax data has shown that intergenerational mobility?the correlation between one?s own economic outcomes and that of one?s parents?has remained steady for cohorts born between 1971 and 1986 (Chetty et al. 2014a) although the determinants of economic mobility varied considerably across place (Chetty et al. 2014b). In particular, residential segregation, income inequality, and worse primary schools are associated with lower rates of economic mobility. The first result seems surprising for those familiar with Alan Krueger?s ?Great Gatsby Curve? (2012), which shows that countries with higher income inequality have lower rates of economic mobility. It is also surprising given that the growing gap in college enrollment and completion is highly correlated with parents? incomes (Bailey and Dynarski 2011).
Chetty et al.?s (2014a) conclusions of relative stability, however, are limited by the time horizon. Income inequality has changed considerably over the last 80 years, both narrowing during the 1940s and widening since 1960. But our understanding of the evolution of economic mobility over the same 80 years is hindered by data (Aaronson and Mazumder 2008). Whether the present is a departure from the past and whether the correlates of mobility have changed over time remain important open questions.
This project makes use of the public version of the Social Security Numerical Identification (NUMIDENT) Files, which was recently released by the National Archives and Record Administration. This file includes form SS-5 information (Application for a Social Security Card) for over 40 million individuals that died before 2007. SS-5 records list the number holder?s full name, date of birth, and place of birth. Crucially, the number holder?s parents? full names are also listed, which provides the link between parents and children needed for estimates of intergenerational mobility.
