Funding K-12 education is one of the best investments the US can make, but public education remains severely underfunded even today. Until schools and districts get the money they need, they must choose which policies to enact based on how cost-effective they are instead of following policies that only provide limited benefits. One popular policy is reducing class sizes and student-teacher ratios, which some studies show increase student achievement. However, while class-size reduction can be effective, it is not always efficient. Instead of hiring more educators to teach smaller classes, there are better methods of improving the quality of education from existing teachers.

The Tennessee Student Teacher Achievement Ratio (STAR) project is the most credible class-size study conducted, and it supports the conclusion that smaller class sizes lead to better outcomes. The study compared kindergarten through 3rd-grade students in small classes of 13-17 people, regular classes of 22-25 people, and regular classes with an aide of 22-25 people. It found that students from smaller classes scored higher on tests, had better grades, enrolled in foreign language classes more frequently, and passed English language requirements more often. Four years after the study, the reduction was equivalent to three additional months of schooling. All in all, the class size reduction’s economic benefits outweighed the costs and was particularly beneficial for disadvantaged students.

However, while the STAR research provided results for large reductions of up to 12 students for early grades, other credible studies have not had comparable results, nor have they extended the STAR study’s conclusions. Studies conducted in Texas produced smaller gains, studies in California and other countries have produced mixed results, and studies in Florida and Connecticut have found no results. In 2033, Florida enacted a law that reduced classroom sizes, which was rolled out over the course of eight years. Costing $4-5 billion annually, the law was found to have no impact on test scores in math or reading. Many conditions in California and Florida were non-ideal and affected the impact class-size reduction had on student achievement, such as low teacher qualifications and overcrowding in schools. In California, the increase in unqualified teachers actually increased the gap between minority or disadvantaged students with the rest of the population.

It can be unclear if the benefits to reducing class sizes outweigh the cost, and there is a lack of data on the effect of reducing class sizes in higher grades. Because it is not feasible for schools to reduce class sizes by 7+ people, as tested in the STAR study, benefits are murky when class sizes only shrink by a few people. In fact, it may be inefficient to reduce class sizes and spend more money to hire teachers if classes only decrease by one or two students.

Instead, there are more effective policies to spend money on. Dr. Nathan Oakley, Chief Academic Officer of the Mississippi Department of Education (MDE), explains that MDE is funding initiatives that improve the quality of instruction for teachers who are already in place.

“The quality of the content being used in the classroom, the instructional materials, the texts, the resources, tools, all play a significant role in student outcomes,” Oakley said. “[We] look at your instructional content, what are you using in the classroom, if it’s aligned to the state’s academic standards, and how are you supporting teachers and professional learning to get better at their craft to address the needs of students.”

Instead of shrinking class sizes and hiring more teachers, MDE’s policies enhance classroom materials and resources, along with aiding with teacher training as opposed to hiring a new wave of teachers. With the extra COVID-19 federal funding the department has received, the focus is on increasing the quality of classroom materials and support.

“We prioritize that [extra funding] on high dosage tutoring supports, after school tutorial and summer tutorial for students that need that, as well as high-quality instructional materials, and online professional learning,” Oakley said. “We’ve encouraged districts to take on some similar projects with their local allocation of funding.”

After-school tutorials in particular have been found to increase student performance, especially programs that target students who are falling behind that class-size reduction aims to help. One study from Nobel-winning economists tested the effect of remedial programs in India, where tutors with no teaching accreditation helped struggling students, ultimately boosting their literacy and math test scores. Significant scores increases remained after one year. Another study in the Philippines determined that struggling fifth-graders who received remedial help performed better than those who did not, and a study of American community college students found that academically underprepared students were more likely to succeed if they completed remedial programs.

Though class-size reductions can provide benefits and are especially helpful for early grade, disadvantaged students, they are usually not conducted on a scale that is effective. Large reductions in class size are unrealistic and can lead to an increase of underqualified teachers, which can actually harm students when external conditions are not properly addressed. While reducing class sizes could have an impact in an ideal world, it’s not enough to justify spending that much money on. Instead, there are more effective policies to enact that help existing teachers become better educators, particularly remedial or tutoring programs.