This study found that gaps in educational achievement between high- and low-income children are growing. According to the results, 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. The implications of this study indicate a need for greater emphasis on program evaluations and to better target resources to help such students who are at-risk educationally.
Michaelmore, K., & Dynarski, S. (2017). The gap within the gap: Using longitudinal data to understand income differences in educational outcomes. AERA Open, 3(1), 1-18.