Three studies of Massachusetts school finance reforms from the 1990s found similar results. The first, by Thomas Downes and colleagues found that the combination of funding and accountability reforms “has been successful in raising the achievement of students in the previously low-spending districts.” (Downes, Zabel & Ansel, 2009, p. 5) The second found that “increases in per-pupil spending led to significant increases in math, reading, science, and social studies test scores for 4th- and 8th-grade students.”(Guryan, 2001) The most recent of the three, published in 2014 in the Journal of Education Finance, found that “changes in the state education aid following the education reform resulted in significantly higher student performance.”(Nguyen-Hoang & Yinger, 2014, p. 297)...but that we are among the states that have lost significant ground over the past several years in how we funding education.
It's worth noting that in their reaction to the passage of ESSA, the Education Law Foundation called out funding equity as something Congress missed:
Most states are shortchanging schools the funding and programs needed to give all children the chance to succeed, especially the growing numbers of children in poverty in districts and states across the country. Millions of children in our state systems attend schools deprived of the teachers, support staff and other resources essential to learning.While creating the foundation budget in 1993 worked, it's past time to update it.