Matthias Pellerin worked with Professor Andrew Foster on a project examining the role of sample weights in the measurement of economic mobility in the United States using the Panel Study of Income Dynamics. This is the only comprehensive nationally representative panel survey in the U.S. that connects origin and descendant households over a period of 40 years. The challenge with such survey data is that the descendants of a given set of households at one point in time are not necessarily representative of the population at a later date unless representative weights are used. But accurately calculating weights requires more information than is typically available from a survey. Existing weights are particularly problematic in cases of mixed-race couples and blended families. Pellerin and Foster are developing an alternative approach that allows for greater precision of estimates of mobility among this population. The Stone Center has been critical to the progress of this project, as it brings together a faculty member with strong substantive interests and experience with this type of a problem and a graduate student who sees himself primarily as an econometrician.