Access to IRS personal income tax records improves researchers' ability to track U.S. income and inequality, especially at the very top of the distribution (Piketty and Saez 2003). However, rather than following standard Haig-Simons income definitions, tax form income measures were designed to...

The cross-national intragenerational income mobility literature assumes within-country mobility is invariant over the period measured. We argue that a great social transformation--German reunification-- abruptly and permanently altered economic mobility. Using standard measures of mobility (with...

There are several ways to measure fatness and obesity, each with its own strengths and weaknesses. The primary measure for tracking the prevalence of obesity has historically been body mass index (BMI). This paper compares long-run trends in the prevalence of obesity when obesity is defined...

Recent research on United States levels and trends in income inequality vary substantially in how they measure income. Piketty and Saez (2003) examine market income of tax units based on IRS tax return data, DeNavas-Walt, Proctor, and Smith (2012) and most CPS-based research uses pre-tax,...

Although the vast majority of US research on trends in the inequality of family income is based on public-use March Current Population Survey (CPS) data, a new wave of research based on Internal Revenue Service (IRS) tax return data reports substantially higher levels of inequality and faster...