Study: Teaching force grew at more than double the enrollment rate

Researcher: Parents want more programs, smaller class sizes; that requires more staff
While student enrollment in the nation’s public, private and charter schools rose by 22% during the past three decades, the teaching force ballooned by more than double that rate, 54%, according to a new study.

Credit: Lhys/

Credit: Lhys/

While student enrollment in the nation’s public, private and charter schools rose by 22% during the past three decades, the teaching force ballooned by more than double that rate, 54%, according to a new study.

An updated longitudinal study on the K-12 teaching force shows a surprising trend over the past three decades. While student enrollment in the nation’s public, private and charter schools rose by 22% during that time, the teaching force ballooned by more than double that rate, 54%.


The reason, suggests the lead author of Seven Trends: The Transformation of the Teaching Force,” is that schools and school boards can’t reject escalating demands from parents and lawmakers for new programs, from computer coding to mental health services, to civics education to Chinese immersion.

“All these demands by parents are very understandable, such as lower class size,” said University of Pennsylvania researcher Richard Ingersoll, the leading expert on America’s teaching force. “Who wouldn’t want their child to be in a class of 18? And, yes, let’s teach Mandarin and, yes, let’s bring back Latin. There are so many demands but very little recognition of the costs.”

For example, lowering class size is a popular reform, said Ingersoll. “Every parent wants it. It is also a very expensive reform. You have to hire more teachers.”

(Before critics of public education blame teacher unions for the larger workforce, teaching ranks in private schools inflated at a faster clip than in public schools, even while private school enrollment fell during the same period.)

Another factor in swelling teacher numbers from 1987 to 2018 is the growth of bilingual programs and special education. The study notes special education classes average about half the size of typical classes in elementary and secondary schools, and special education is a relatively large field (11% of all teachers). The upsurge in special education teachers accounts for about 15% of the increase in the teaching force.

Richard Ingersoll of the University of Pennsylvania. (Courtesy of Stuart Goldenberg)

Credit: Stuart Goldenberg

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Credit: Stuart Goldenberg

The national focus on STEM education and expanded high school graduation requirements in math and science also play a role. The number of math teachers leapt by 78%, while the number of teachers of science jumped 84%.

While public schools are admonished to operate like businesses, Ingersoll says schools aren’t free to define their mission and stick to it. “The school system, in a sense, is an instrument of communities and local property taxes. So, they get this whole fragmented series of missions. This is the whole problem — they have to do umpteen things. Private schools and charter schools can specialize. They can tell parents we only do these five things and we do them well. We don’t do these other things.”

In what Ingersoll said is a century-long trend, schools are being deputized to teach skills once regarded as the responsibility of communities, churches or families, such as balancing a checkbook. “My own personal view is that we need to have more focus. Delimit the objective and do fewer things better. Schools become scapegoat and savior for all these societal ills,” he said in a telephone interview.

With the teacher numbers growing at twice the rate of the student population to meet all these new mandates, Ingersoll foresees an eventual reckoning. “Who can afford these increasing teacher salaries? For school districts, the ballooning trend is alarming because, in my own guess, it is unsustainable in the long term.”

But Ingersoll’s study uncovered another trend helping a bit to suppress the salary arc — a dramatic increase in the number of teachers who are beginners, described as the “greening” of America’s teaching corps.

“The whole ratio of beginners to veterans has completely changed,” he said. “There are far more teachers at the low end of the salary schedule. But do you want a situation where the senior teacher in the building is someone in their fifth year?”

In the past, there were concerns about the “graying” of the teacher force. But Ingersoll’s analyses confirm that while the profession has aged, the graying is over. The most common age of a teacher was 55 in 2007-2008. In recent years, the most common age has spread out — ranging from the low 30s to the high 40s.

Along with a larger and greener profession, the study found the workforce became less diverse by gender. The study notes: “We may see a day when 8 of 10 teachers in the nation will be female. An increasing percentage of elementary schools will have no male teachers.”

On the other hand, the study discovered the teacher ranks became more diverse by race-ethnicity. Minority recruitment efforts have succeeded; minorities entered teaching at higher rates than whites in recent decades, said Ingersoll. However, they also quit at higher rates, especially Black males who are often called upon to be mentors, role models and coaches.

“Schools get Black male teachers and, they’re so glad to get them, they work them to death. I am not sure if the word here is irony or tragedy,” said Ingersoll.

The higher rates of turnover among minority teachers contribute to the overall instability of the education profession. What drives the high turnover rate among minority teachers are their working conditions, said Ingersoll.

“How much discretion are teachers allowed in their classroom? How much of a collective voice does the faculty have in key decisions in the building?” he said. “That lack of discretion was the biggest single factor behind those high quit rates.”

Fixing those conditions does not cost a lot of money but does demand eliminating top-down edicts and tightly scripted classrooms.

“With standardized curricula and testing, large urban districts have gone in the opposite direction. There is less discretion in classrooms. They want all ninth grade math teachers teaching to the same page, to the same test on the same day. What teachers are saying is hold me accountable, but don’t tell me how to get from A to B.”

Ingersoll recognizes the appeal of scripted instruction. “There is some validity to it. We want consistency across classes. And for weaker teachers, having this scripted curriculum is helpful. But for your top teachers, it drives them batty to be micromanaged.”

Teacher morale was further bruised by COVID-19, which pitted the health concerns of educators against the needs of parents to return to work. Whether that disillusionment will drive people out of the profession at accelerated rates won’t be discernible for a while, said Ingersoll.

“People don’t leave their jobs and they don’t retire in down economic times: When COVID is over, and, if and when the economy recovers, there could be a pent-up situation that releases,” he said. “A whole bunch of teachers may say now I can finally retire and don’t have to be afraid my 401(k) is going to shrink. We might see that in a year.”