The Gap Within the Gap: Using Longitudinal Data to Understand Income Differences in Student Achievement

Working Paper: NBER ID: w22474

Authors: Katherine Michelmore; Susan Dynarski

Abstract: Gaps in educational achievement between high- and low-income children are growing. Administrative datasets 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 datasets to develop a new measure of persistent economic disadvantage. Half of 8th graders in Michigan are eligible for a subsidized meal, but just 14 percent have been eligible for subsidized meals in every grade since kindergarten. These children score 0.94 standard deviations below those never eligible for subsidies and 0.23 below those occasionally eligible. There is a negative, linear relationship between grades spent in economic disadvantage and 8th grade test scores. This is not an exposure effect: the relationship is almost identical in 3rd grade, before children have been differentially exposed to five more 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 current household income. Years eligible for subsidized meals can therefore be used as a reasonable proxy for income. Our proposed measure can be used in evaluations to estimate heterogeneous effects, to improve value-added calculations, and to better target resources.

Keywords: Income Disparities; Student Achievement; Longitudinal Data; Economic Disadvantage

JEL Codes: I24; I28; I32


Causal Claims Network Graph

Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.


Causal Claims

CauseEffect
years spent in economic disadvantage (P46)test scores (C52)
persistent economic disadvantage (I32)test scores (C52)
additional year of economic disadvantage (J14)worsening academic performance (D29)
economic disadvantage (I32)achievement gap (I24)
economic disadvantage (I32)early academic effects (I21)

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