US teacher strikes were good, actually

Few things have bedeviled education policy researchers in the US more than public school teacher strikes, driven by educators on the vanguard of resurging labor activism. While union membership nationwide continues to decline, nearly one in five union members in the US is a public school teacher — and their high-profile, disruptive strikes generate significant media attention and public debate.

But do these strikes work? Do they deliver gains for workers? Do they help or hurt students academically? 

Answering these questions has been challenging, largely due to a lack of centralized data that scholars could use to analyze the strikes. The Bureau of Labor Statistics used to keep track of all strikes and work stoppages across the country, but since its budget was cut in the early 1980s, the agency has only tracked strikes involving more than 1,000 employees. Given that 97 percent of US school districts employ fewer than 1,000 teachers, the majority of teacher strikes are not federally documented.

Now, for the first time ever, researchers Melissa Arnold Lyon of the University at Albany, Matthew Kraft of Brown University, and Matthew Steinberg of the education group Accelerate have compiled a novel data set to answer these questions, providing the first credible estimates of the effect of US teacher strikes. 

Their data set — which covers 772 teacher strikes across 610 school districts in 27 states between 2007-2023 — took four years to compile. The three co-authors, plus seven additional research assistants, reviewed over 90,000 news articles to plug the gaps in national data. Their working paper, which will be published tomorrow, provides revealing information about the causes and consequences of teacher strikes in America, and suggests they remain a potent tool for educators to improve their working conditions. 

Teacher strikes lead to significant wage increases on average, regardless of length

By and large, teacher strikes in the US are not common, nor are they lengthy work stoppages. The median number of strikes per year over the 16-year study was 12.5, with the typical strike lasting just one day. Sixty-five percent of strikes ended in five days or less. Their longest identified strike was 34 days in Strongsville, Ohio in 2013.

Almost 90 percent of the teacher strikes identified involved educators calling for higher salaries or increased benefits, and the researchers found that, on average, strikes were successful in delivering those gains. Specifically, the strikes caused average compensation to increase by 3 percent (or $2,000 per teacher) one year after the strike, reaching 8 percent, or $10,000 per teacher, five years out from the strike. 

More than half of strikes also called for improved working conditions, such as lower class sizes or increased spending on school facilities and non-instructional staff like nurses. The researchers found that strikes were also effective in this regard, as pupil-teacher ratios fell by 3.2 percent and there was a 7 percent increase in spending dedicated to paying non-instructional staff by the third year after a strike.

Importantly, the new spending on compensation and working conditions did not come from shuffling existing funds, but from increasing overall education spending, primarily from the state level.

That these strikes were effective is notable, particularly since labor strikes overall have not been associated with increases in wages, hours, or benefits since the 1980s. The study authors suggest strikes among public school teachers may be a more “high-leverage negotiating tactic” than other unionized fields because teachers can be less easily replaced by non-unionized workers or tech automation. 

Perhaps surprisingly, the researchers find no relationship between whether a strike is short or long in terms of the effect it has on teacher salary.

Lyon of the University at Albany thinks that part of why teachers may be so successful in achieving such significant increases is because teacher strikes can send public signals in ways other labor strikes often can’t. 

“Because education is such a salient industry, even a one-day strike can have a big impact,” she told me. “News media will pick it up, people will pay attention, and parents are going to be inconvenienced. You have these built-in mechanisms for attracting attention that other types of protest do not.” Another study she co-authored with Kraft earlier this year found that teacher strikes more than double the probability of US congressional political ads mentioning education, underscoring their power in signaling the need for educational change.

Students were not academically harmed by the strikes

Previous research on teacher strikes in Argentina, Canada, and Belgium, where work stoppages lasted much longer, found large negative effects on student achievement from teacher strikes. (In the Argentina study, the average student lost 88 school days.) 

In contrast, the researchers find no evidence that US teacher strikes, which are much shorter, affected reading or math achievement for students in the year of the strike, or in the five years after. While US strikes lasting two or more weeks negatively affected math achievement in both the year of the strike and the year after, scores rebounded for students after that. 

In fact, Lyon said they could not rule out that the brief teacher strikes actually boosted student learning over time, given the increased school spending associated with them. A recent influential meta-analysis on school finance found that increasing operational spending by $1,000 per student for four years helped student learning. 

It’s possible higher wages could reduce teacher burnout, or the need to work second jobs, leading to improved performance in the classroom. Still, Lyon explained, it’s also possible that increased spending on teachers would not lead to higher student test scores, if wage gains went primarily to more experienced teachers, or to pensions, or if teachers were already maximizing their effort before the strike. 

Strikes were more common in conservative, labor-unfriendly areas

Overall, the researchers found that teacher union density has fallen more sharply than previously recognized. According to federal data, 85 percent of public school teachers reported being in a union in 1990, falling to 79 percent in 1999, and then to 68 percent by 2020.

“As someone who studies unions, that statistic alone is still pretty surprising to me,” Lyon said. “And it came from the federal Schools and Staffing Survey, which is one of our best data sources.” Tracking teacher union membership can be complicated because of mergers, and because the two national unions — the American Federation of Teachers and the National Education Association — include non-teachers and retired teachers in their ranks. Still, even with the drop, the 68 percent dwarfs that of the private sector, where just 10 percent of workers are in unions. 

Roughly 35 states have laws that either explicitly ban or effectively prohibit teacher strikes, but those laws haven’t stopped educators from organizing labor stoppages. (Nearly every state in the #RedforEd teacher strikes from 2018 and 2019 — including Arizona, Kentucky, West Virginia, and Oklahoma — had banned teacher strikes.)

In compiling their data set, Lyon, Kraft, and Steinberg included both legal strikes and illegal work stoppages, including mass walk-outs, “sick-outs” (when teachers call in sick en masse), or so-called “wildcat strikes” (when educators strike without the support of union leadership).

Perhaps counterintuitively, they found strikes were more common in more conservative, labor-hostile states, something they attributed mostly to large-scale coordinated strikes across districts happening more often in those places. Individual district strikes were more likely to occur in liberal areas, where such actions are legal.

The teacher uprisings over the last decade have helped boost support from parents and the broader public, who report in surveys backing for educator organizing and increased teacher pay. The percentage of the public who see teacher unions as a positive influence on schools rose from 32 percent in 2013 to 43 percent in 2019, according to Education Next polling. A majority of the US public supports teachers having the right to strike, which suggests educators may be comfortable using this tactic going forward.