Comments on class size paper by Matthew Chingos and Ariella Meltzer

August 3, 2023

Comments on paper by Matthew Chingos and Ariella Meltzer, “Class Size Reductions May Be Inequitably Distributed under a New Mandate in New York City”

The primary claim made in this paper is that lowering class size would inequitably benefit white and Asian students rather than Black and Hispanic students, who tend to have lower class sizes already in NYC public schools.

However, several points appear to undermine that claim:

1. As much research shows,  Black and Hispanic students as well as students in poverty tend to gain twice the benefits in terms of increased learning and non-cognitive skills from smaller classes compared to their peers. Thus class size reduction is one of only a very few reforms that have been proven through rigorous research to narrow the achievement/opportunity gap and represents a key driver of education equity. Only 8% of high-poverty NYC schools already comply with the class size caps in the law, according to the Independent Budget Office.

2. The estimates in Table A2 of this paper project that Black students would see their class sizes reduced on average to 16.7 students per class, the smallest class size of any group, with Hispanic, low-income, and students with disabilities second at 17.3, a highly equitable outcome.  English language learners would come next at 17.4.  In short, all high-needs groups would receive smaller classes than non-low income students ( at 17.6),  White students (at 17.7) or Asian students (at 18 students per class)

3. Finally, the paper’s findings also show that English language learners students at the elementary school level are more likely than non-ELLs to have large classes even now, and thus would likely gain substantial benefits from class size reduction as well.

There will be challenges for sure, to ensure that lowering class size doesn’t drain more experienced teachers from the neediest schools, but this could be avoided by targeting high-poverty schools first for class size reduction, as the law requires.

In addition, there are several studies that suggest that class size reduction may lower teacher attrition, especially at the highest-poverty schools, so that in the long run, the effort may lead to a more effective, stable, and experienced teaching force over time.

Our questions are these:

1 – Why cite the IBO cost estimates of 17,700 additional teachers needed, of  $1.6 to $1.9 billion annually while relegating  DOE’s far lower estimates of 9,000 new teachers at $1.3B to a footnote?  Did the authors decide one estimate was more authoritative than the other, and if so why?

2-The authors also cite an early School Construction Authority estimate of $30B-$35B for capital expenses, yet the SCA has admitted that this was “a back of the envelope” estimate and now has been omitted from the DOE’s updated version of their draft class size plan posted in July, as compared to an earlier version submitted in May. So why did they include it at all, if not to exaggerate the potential costs?