ck, and Andrew (2007) , our measure of retention in the g th grade is based on a comparison of grade of enrollment across consecutive years. Among students attending grade g last year, those attending grade g this year have been retained; those attending grade g +1 have made normal progress; and those attending grade g +2 have skipped a grade. In Table 1 , we cross-classify grade of enrollment last year by grade of enrollment this year for the 252,128 people who were enrolled in grades 1 through 9 in the year preceding their interviews in 1995 through 2010. As shown in Table 1 , the vast majority of students make normal progress, and only a very small number skip grades. Table 1. Cross-Classification of Students’ Grade of Enrollment THIS Year by their Grade of Enrollment LAST Year, 1995–2010 Open in a new tab Note: Analysis based on 1995–2010 Current Population Survey (CPS) Data. Sample excludes children with imputed values on grade of enrollment this year or last year. Analyses weighted by the CPS October Supplement Weight (after normalizing the weight to have a mean of zero). We make a number of important technical improvements in our measure as compared to that produced by Hauser, Frederick, and Andrew (2007) . First, we exclude students whose grade of enrollment (this year and/or last year) was not actually reported by the CPS respondent. In about one in every seven cases, the CPS imputed values using procedures that are not well documented, that frequently produce implausible values, and that consequently create the impression that many students skipped multiple grades or even moved backward in grade across years. Second, we exclude some cases in which grade of enrollment (this year and/or last year) was reported but appears to be implausible (i.e., because the student appears to skip many grades or move backward in grade). Close inspection of the data leads us to believe that some respondents misunderstand response options (e.g., confusing “first grade” for “f