CRPE: Small classes have high costs

The benefits of small classes — more individual attention, less teacher stress — may not outweigh the costs in dollars and teacher quality, concludes The Opportunity Cost of Smaller Classes, a state-by-state analysis by the University of Washington’s Center for Reinventing Public Education. Call sizes in 2011-12 were slightly smaller than in 1999-2000, countering “the common and mistaken belief — spurred on by knee-jerk sensationalism and politicking — that class sizes are ‘skyrocketing’,” writes Education Gadfly.

The authors demonstrate that increasing the nation’s average class size by just two students could free up $15.7 billion—enough to raise average teacher salary by $5,000 per teacher, provide a laptop for every student, or lengthen the school day in the poorest quintile of schools.

Limiting K-3 class size to 14 to 17 students in high-poverty elementary schools showed lasting benefits, especially for blacks, in the Tennessee STAR study. (Some argue all the benefits accrued in kindergarten and first grade.)

Inspired by STAR, California paid all elementary schools $1 billion-plus a year to lower class sizes to 20 in K-3.  Suburban schools were able to hire competent teachers for the new classes. Urban schools with hard-to-teach kids filled classrooms with less-qualified candidates, a follow-up study found. The study found no evidence smaller classes improved student achievement. Because of the very high costs, schools spent less on other needs, including maintenance, teacher training, libraries and technology. Music, art, sports and special ed lost space on campuses. (I’ve seen schools cover their playing fields with portable classrooms.)

“Very large class-size reductions, on the order of magnitude of 7-10 fewer students per class, can have significant long-term effects on student achievement . . . in the earliest grades, and for students from less advantaged family backgrounds,” write Brookings’ Russ Whitehurst and Matthew Chingos. But is it the best use of education dollars?  “One careful analysis of several educational interventions found CSR to be the least cost effective of those studied.”

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  1. cranberry says:

    According to the report, the writers used the formula: 1. Average Class Size (ACS) x Number of Teachers (NT)/New Class Size = New Number of Teachers.

    The math isn’t that simple. I compared the actual class size one of my children had about five years ago. The actual class size was over 20. The student-teacher ratio given by the state was slightly over 10.

    Why? Well, our district uses many ed specialists, classroom aides, etc. Many of the aides are licensed teachers, waiting for a classroom teaching slot to open up. Sped instruction depends upon a cadre of special education specialists, who are tasked with the welfare of the mainstreamed students with IEPs.

    Some of the school systems in our area are moving to a two-teacher per class model, to support mainstreaming. They are reportedly reducing foreign language instruction to free up funds for the “team teaching” model.

    Thus, adding two students per class wouldn’t have increased class size from 10 to 12. It would have increased class size from 21 to 23. Two teachers teaching a large mainstreamed class are not the equivalent of two teachers teaching two classes which are half the size of the mainstreamed class.

    The student/teacher ratio can be low, but the average kid without an IEP may be facing classrooms filled with many students. Learning specialists are not teaching classrooms. They work with a much smaller subset of students.

    Parents support smaller class sizes because they are aware of the challenges mainstreamed classrooms pose for teaching.

    The math is much simpler in private schools, as they may have a few learning specialists, but they don’t offer the same support for learning disabilities.

  2. Years ago, class size was much larger. My 1-8 class was about 35 kids and that was about average for public schools, AFAIK. Catholic schools were often MUCH bigger – my DH had 100 kids, one nun and one yardstick. (my teachers only had rulers). Discipline was much stricter and was supported by parents, which made/makes a difference. My kids’ classes were in the mid-upper 20s. Even my kids were out of ES-MS before the mainstreaming push hit, which also makes a difference.

    • My school technically has a teacher/student ratio of 13, but my classes are always over 25.

  3. Mike in Texas says:

    The most influential and credible study of CSR is the Student Teacher Achievement Ratio, or STAR, study which was conducted in Tennessee during the late 1980s. In this study, students and teachers were randomly assigned to a small class, with an average of 15 students, or a regular class, with an average of 22 students. This large reduction in class size (7 students, or 32 percent) was found to increase student achievement by an amount equivalent to about 3 additional months of schooling four years later

    Only a group of right-wing nutjobs would quote facts from the definitive study on something and then try to reach the exact opposite conclusion.

    Please note the word “credible”. Their word, not mine, but yet they somehow conclude its not worth it.

    • Mark Roulo says:

      This is the conclusion that they reach:

      …it appears that very large class-size reductions, on the order of magnitude of 7-10 fewer students per class, can have significant long-term effects on student achievement and other meaningful outcomes. These effects seem to be largest when introduced in the earliest grades, and for students from less advantaged family backgrounds.


      When school finances are limited, the cost-benefit test any educational policy must pass is not “Does this policy have any positive effect?” but rather “Is this policy the most productive use of these educational dollars?” Assuming even the largest class-size effects, such as the STAR results, class-size mandates must still be considered in the context of alternative uses of tax dollars for education. There is no research from the U.S. that directly compares CSR to specific alternative investments, but one careful analysis of several educational interventions found CSR to be the least cost effective of those studied.

      What “exact opposite conclusion” did they reach from the one that you think they should have reached?

      • Mike in Texas says:

        “”One careful analysis of several educational interventions found CSR to be the least cost effective of those studied.”

        • Mark Roulo says:

          So they claim:
          (a) Smaller class sizes have a positive benefit, and
          (b) For the same amount of money one can get larger benefits with other changes
          And this makes them “right-wing nutjobs”.
          Am I summarizing correctly?

  4. As with other areas of education, it’s culturally dependent. I walked into an AP English class. This class had 42 students, (I counted). They were on the floor, on window ledges, and in the 30 desks that were allotted for the classroom. However, the teacher was speaking in a normal voice, the students were paying attention and the only sound you could here was the instruction. How was it done? Motivated, upper socio-economic kids. Serious students who did the work.