K12 POLICY This all about the politics of money and nothing about K12 education at all.
Persistent economic disadvantage and education inequality in the United States – How economic disadvantages affect standardized test scores.
In test scores in the 8th grade between students who are occasionally eligible for subsidized lunches and those who have been eligible every single year since kindergarten. The two economists consider students who have been eligible every year (14 percent of Michigan students) to be persistently disadvantaged. And they find that these students score a full standard deviation below kids who have never been on subsidized lunches (40 percent of students) and just under a quarter below students who are occasionally eligible for subsidized lunches (roughly 45 percent of students). (A standard deviation being further away from something than a quarter standard deviation.)
The difference between persistently-eligible students and occasionally-eligible students is a sign that the former are from much lower-income backgrounds. It’s a story of income inequality, not income volatility.