Hanusheuk, E., Peterson, P., Talpey, L., & Woessmann, L. (2019, Summer). The Achievement Gap Fails to Close: Half century of testing shows persistent divide between haves and have-nots. Retrieved March 20, 2019.

Student achievement gaps have not changed in about 50 years, according to a study by researchers at Stanford and Harvard universities. Researchers say the gap remains despite gains in student achievement through eighth grade and increased investments in education.