The Gap Within the Gap - Using Longitudinal Data to Understand Income Differences in Educational Outcomes

Oct 15, 2026

Uploaded by Cipher

Educational achievement gaps between high- and low-income children are widening, while common administrative datasets lack direct income measures. This article introduces a longitudinal measure of economic disadvantage using students’ repeated eligibility for subsidized school meals. Evidence from Michigan shows persistent eligibility is associated with substantially lower test scores and a near-linear relationship with years spent disadvantaged. Results also indicate timing matters and the approach can support program evaluation, improved value-added estimates, and targeted resource allocation.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages18

Reading Time45 min

AccessFree to download

Background

Administrative data and meal eligibility as a proxy

Developing a longitudinal measure of economic disadvantage

Empirical findings on test scores and timing

Applications for program evaluation and targeting

AERA Open January-March 2017, Vol. 3, No. 1, pp. 1–18 DOI: 10. 1177/2332858417692958 © The Author(s) 2017. [http://ero.sagepub.com](http://ero.sagepub.com) The Gap Within the Gap: Using Longitudinal Data to Understand Income Differences in Educational Outcomes Katherine Michelmore Syracuse University Susan Dynarski University of Michigan Gaps in educational achievement between high-and low-income children are growing. Administrative data sets maintained by states and districts lack information about income but do indicate whether a student is eligible for subsidized school meals. We leverage the longitudinal structure of these data sets to develop a new measure of economic disadvantage. Half of eighth graders in Michigan are eligible for a subsidized meal, but just 14% have been eligible for subsidized meals in every grade since kindergarten. These children score 0.94 standard deviations below those who are never eligible for meal subsidies and 0.23 below those who are occasionally eligible. There is a negative, linear relationship between grades spent in economic disadvantage and eighth-grade test scores. This is not an exposure effect; the relationship is almost identical in third-grade, before children have been exposed to varying years of economic disadvantage. Survey data show that the number of years that a child will spend eligible for subsidized lunch is negatively correlated with her or his current household income. Years eligible for subsidized meals can therefore be used as a reasonable proxy for income. Our proposed measure can be used to estimate heterogeneous effects in program evaluations, to improve value-added calculations, and to better target resources. Keywords: achievement gaps, chronic poverty, education inequality Gaps in student achievement between high-and low-income children are growing. The poverty gap in standardized test scores is 40% larger today than it was 25 years ago and is twice as large as the Black-White gap (Reardon, 2011) .1 Test scores are an early predictor of educational attainment and income in adulthood: a one-standard-deviation difference in test scores in grade school corresponds to a 5-percentagepoint difference in college attendance and a 9% difference in earnings at age 28 (Chetty, Friedman, & Rockoff, 2011) . A large literature studies the link between family resources in childhood and educational outcomes.2 Studies that exploit longitudinal data show that deficits are particularly large forchildren who are persistently disadvantaged.3 But the household surveys that these studies rely upon are infrequent and suffer from nonresponse and attrition.4 The administrative data sets increasingly analyzed by education researchers (Dynarski & Berends, 2015) do not have these weaknesses but typically contain a single, crude proxy for income: an indicator of students’ eligibility for federally subsidized school meals. Children in households with income below 185% of the federal poverty line are eligible for subsidized meals in school. Subsidized-meal eligibility is widely used by researchers as a proxy for poverty. But nearly half of students nationwide are eligible for subsidized meals, whereas only a quarter of U.S. children live in poverty. These two statistics make clear that eligibility for subsidized meals is a blunt measure of economic disadvantage. It is, for now, the only measure available to the many researchers and practitioners who work with administrative data to evaluate the effects of educational programs, measure gaps in student achievement, and steer resources toward the most needy children. We use administrative data from Michigan to develop amore detailed measure of economic disadvantage. Our data contain information on the entire population of students in the Michigan public schools. We leverage the longitudinal nature of these data to document systematic variation in outcomes and disadvantage within the population of children who are eligib

FAQs

Why do the authors develop a new measure of economic disadvantage?

Administrative education datasets typically indicate subsidized-meal eligibility but not income. The paper leverages the longitudinal structure of these records to construct a more detailed economic disadvantage measure tied to repeated eligibility.

What relationship is found between years of disadvantage and test scores?

The study finds a negative, nearly linear relationship between the number of grades spent in economic disadvantage and eighth-grade test scores, with a similar pattern observed in third grade before children have accumulated different exposure years.

How can the proposed measure be used in practice?

The measure can estimate heterogeneous effects in program evaluations, improve value-added calculations, and help target educational resources toward the most economically disadvantaged students.

Oct 15, 2026

Uploaded by Cipher