As America’s students begin the new school year, they’re facing historic learning deficits.
Elected officials have failed to confront the crisis and help students make up lost ground.
Instead, many have been turning to a policy that will aid their re-election efforts without helping kids: mandating smaller classes.
Class-size mandates are a favorite policy of the teachers’ unions, not least because they often require districts to hire more unionized teachers.
They also prevent layoffs at schools where enrollment is falling.
Smaller classes would be worth the enormous new expenditures on staff and facilities if they produced the results that supporters tout — but, as experience and data show, they don’t.
Although students can be more engaged in smaller classes, achievement gains — where they appear at all — are small, mostly limited to younger grades, and concentrated in seminar-style settings with very few students that are impossible to replicate at scale.
One study found that, compared to investments in technology, tutoring, early-childhood programs and other policies, class-size reduction was the least cost-effective way to improve student learning.
A 2018 review of 148 reports from 41 countries concluded that smaller classes had “a very small” effect on reading proficiency and no effect on math, despite the enormous outlays for them.
Nevertheless, most states now regulate class sizes in some manner, ranging from prescribed teacher-student ratios to more stringent caps on the number of students allowed in a classroom, with penalties for districts that fail to comply.
And now New York City, the country’s largest public-school district, is being forced to adopt some of the most sweeping measures.
Under new state legislation, the city will be required, starting next year, to reduce maximum class sizes in all public schools from 25 to 20 in kindergarten and from 32 to 20 in grades one through three.
For grades four through eight, class sizes will be capped at 23, with high school classes reduced from 34 to 25.
City officials say they’ll have to hire 17,700 new teachers by 2028 and spend as much as $1.9 billion annually on additional salaries.
That’s on top of about $35 billion the law would require to expand or refurbish the city’s more than 1,500 district schools.
Capping class sizes across the board is unlikely to help the city’s most disadvantaged students and may even hurt them.
Large classes are most prevalent in schools with high enrollment, which also tend to serve more affluent neighborhoods.
Under the new mandate, only 38% of the highest-poverty schools would see class sizes shrink, compared to nearly 70% of medium- to low-poverty schools.
Funding that might otherwise be targeted toward the neediest students will flow to the relatively well off.
And as wealthier, well-attended schools create new positions to meet class-size mandates, low-income schools risk seeing their best teachers opt for those jobs instead.
Class-size laws are a poor use of schools’ limited resources.
Rather than impose heavy-handed mandates, states should give school leaders the flexibility to use funds on other programs, such as intensive tutoring and summer instruction, that are more effective in aiding academic recovery.
Money devoted to hiring new personnel would be better spent rewarding talented teachers and increasing incentives for them to work in underserved areas and in classrooms with struggling students.
It would also help if Democratic leaders were more supportive of high-quality public charter schools, which outperform traditional public schools while receiving far less public funding.
The fact that some also have larger average class sizes speaks to the backwardness of the mandates.
And the fact that enrollment in charter schools has been soaring while enrollment in traditional district schools has been declining shows that parents are voting with their feet.
This year, the New York City teachers’ union sued to keep one of the city’s most successful public charter-school networks (which Bloomberg Philanthropies supports) from locating in an under-used public-school building, because charters are exempt from the new class-size law.
It was an outrageous attack on children, and thankfully, it failed.
But few of the city’s elected officials stood up to the union and supported the charter school and its students and teachers.
The learning-loss crisis demands greater attention from the country’s leaders and more effective policies to address it.
Focusing on class sizes is a feel-good measure that will enhance the power of teachers’ unions.
But it won’t help the students who need it most.
Former Mayor Michael R. Bloomberg is the founder and majority owner of Bloomberg LP. This column first appeared on Bloomberg Opinion.