Receiving a union endorsement increases a school board candidate’s support by 6 to 8 percentage points. Union-endorsed candidates win over 60% of school board races and are more likely to support the favored policies of teachers’ unions. During the COVID-19 pandemic, areas with stronger unions kept schools closed longer, in alignment with union stances on the safety of reopening schools. At the state level, fewer policy reforms that run contrary to the interests of teachers’ unions are enacted in areas where teachers’ unions spend more on candidate donations than other interest groups.
Expenditures in newly unionized school districts increase by 12.3%, on average. When CBAs marginally increase in strength by one standard deviation (s.d.), school districts spend 1.2% more, which equates to approximately $111 more per pupil. Alternatively, right-to-work laws and restrictions on collective bargaining lead to a reduction in school expenditures of approximately 3.8%.
Teacher salaries increase by between 4% and 12% with the onset of unionization or collective bargaining, and they decrease by between 3% and 9% when teachers’ unions and collective bargaining are substantially restricted by state laws. Strong teachers’ unions are also successful in channeling new revenue for schools to teacher salaries. In states with strong teachers’ unions, teacher salaries increase by 84 cents for every $1 increase in state revenue to school districts, compared to just 32 cents for every 1$ in new state revenue in states where the power of teachers’ unions is average.
For every 10% increase in union strength, experienced and novice teachers are 4–7% less likely to turn over. Laws that drastically reduced teacher collective bargaining rights increased teacher turnover by approximately 1% per year and increased retirements by 18% in the year after these reforms were implemented.
Marginal increases in the strength of CBAs have no impact on student achievement. When teachers’ unions are substantially weakened by state policies, research suggests short-run student achievement declines or does not change. However, in the long run, math and reading performance improves.
Teachers’ unions in the United States are membership-based, nonprofit organizations largely funded by dues-paying classroom teachers, education support professionals, higher education faculty and staff, and retired educators. The two largest teachers' unions, the National Education Association (NEA) and American Federation of Teachers (AFT), maintain extensive national organizations. In 2023, the NEA had over 2.8 million members, and the AFT had over 1.7 million members.1 While the National Labor Relations Act (NLRA) (1935) governs the formation of private-sector trade unions, teachers’ unions operate in the public sector, and hence, state and local affiliates of the NEA and AFT are subject to state laws. The diversity of state laws governing the formation and operation of teachers' unions means that the size, scope, and activity of state and local teachers’ unions vary geographically.
The primary function of local teachers’ unions has been to negotiate collective bargaining agreements (CBAs) on wages and working conditions on behalf of their membership. Initially embraced by the AFT, the earliest CBA for public-school teachers was signed by the United Federation of Teachers in New York City, an AFT affiliate, in 1962 after a one-day strike involving over 20,000 educators.2 Today, state laws allow collective bargaining between teachers and their employers through unions in 44 states and prohibit it in 6 states.3 In large school districts, CBAs can be quite lengthy, spanning over 200 pages and covering a wide range of working conditions, including salary, class sizes, work hours, layoffs, health benefits, and time off.4 Even where collective bargaining is prohibited by state law, teachers’ unions informally advocate for better wages and working conditions for teachers.5
Beyond collective bargaining, teachers’ unions organize at the local, state, and national levels to advocate for education policies supported by their membership. They take prominent policy stances on union-specific policies, such as whether and how collective bargaining occurs and how unions are formed and managed, and on education-specific policies, such as curriculum content, teaching standards, teacher evaluation, public school choice, and school safety. Teachers’ unions are also active in political campaigns. In the 2024 election cycle, the NEA and AFT donated nearly $15 million and nearly $13 million, respectively, to the political campaigns of local, state, and federal candidates for office and to specific political causes to facilitate the enactment of policies that they favor.6 In recent years, they have broadened their policy advocacy to extend beyond union-specific or education-specific causes to those focused on “common good” issues such as immigration, housing, racial justice, and healthcare.7
Below, I describe the research on how teachers’ unions’ impact the education system, including their influence on education policy, school expenditures, teacher working conditions, the teacher labor market, and, ultimately, student achievement.
Prior to providing an overview of the research evidence in more detail, I first discuss common perspectives on the impact of teachers’ unions on the education system and then discuss how researchers frequently measure the impact of teachers’ unions and collective bargaining on education.
Perspectives on teachers’ unions in education
The key arguments for teachers’ unions and collective bargaining, sometimes called the voice perspective, primarily center on providing teachers with a voice in their wages and working conditions. Hirschman’s (1970) exit-voice hypothesis argues that workers have two options in regard to their wages and working conditions. First, they can exit and reward a new employer with their expertise and labor, thereby signaling to their old employer that the wages and working conditions were insufficient. The second response, voice, involves the use of collective pressure to bring actual wages and working conditions closer to the desired outcomes. In the case of education, some argue that absent an organized voice, teachers would be subject to the arbitrary and capricious exercise of power by school administrators, which could result in unfair and/or inequitable pay and benefits, larger class sizes, heavier workloads, less safe schools, and, ultimately, higher teacher turnover. Furthermore, the working conditions of teachers are often cited as the learning conditions of students, and through their day-to-day work in America’s classrooms, teachers are best positioned to advocate on behalf of students through their unions.
The key arguments against teachers’ unions and collective bargaining, sometimes called the rent-seeking perspective, center on the routinization and standardization of teaching and schools through the labyrinth of rules found in CBAs. These rules could bind schools to practices that are less innovative and less effective. Furthermore, teachers’ unions may drive up educational expenditures to reward their membership, with less regard for the productivity of these expenditures in yielding positive outcomes for students (such as student achievement and graduation rates), resulting in inefficient practices.8 For example, teachers’ unions may advocate for better working conditions such as lower class sizes, longer planning periods, and shorter work days than would otherwise be optimal or necessary to deliver a high-quality education to students. Furthermore, to deliver these working conditions, school districts may have to spend more money and hire more teachers than would be ideal.9
The tension between the two dominant conceptual perspectives on teachers’ unions, rent-seeking and voice, has been frequently discussed in the literature.10 These perspectives have their advantages. First, they allow a clear framework for understanding what teachers’ unions do within schools to affect school expenditures and student performance. Second, they help forecast what the effects of teachers’ unions might be with new policy changes, such as changes to the scope of collective bargaining, to school finance, and to school choice. Third, they help highlight the context-dependent nature of teachers’ unions, which in some contexts may be rent-seeking, damaging productivity, and in other contexts may amplify voice, enhancing productivity. Below, I provide an overview of the extent to which the literature aligns with these theoretical perspectives, emphasizing what we currently know and do not know about the impact of teachers’ unions and collective bargaining on public education.
Ways to Study Teachers’ Unions and Collective Bargaining
Scholars have studied the impact of teachers’ unions and collective bargaining in multiple ways. One common approach involves examining how outcomes change relative to marginal increases in teachers’ union strength over time. This approach is particularly useful for analyses within states where there is little variation in the presence or absence of unions and collective bargaining (i.e., most school districts have teachers’ unions and collective bargaining).
Marginal changes in teachers’ union strength have been measured in several ways. Stronger unions negotiate better contracts for their members; hence, one way to measure union strength is to assess the strength of the CBA.11 The most important development in capturing CBA strength is Strunk and Reardon’s (2010) partial independence item response (PIIR) model for estimating latent CBA restrictiveness.12 Using information from hand-coding CBAs for over 600 different provisions in California, these researchers generated a valid and reliable measure of CBA restrictiveness (i.e., the degree to which a given CBA limits school and school district leaders in administering schools). This approach has been used in other states, on charter school CBAs, and on COVID-19 pandemic memorandums of understanding (MOUs) with teachers’ unions.13 Beyond CBAs, marginal changes in teachers’ union strength have been captured in other ways. Teachers’ unions spend considerable amounts of money on federal, state, and local elections. Hence, one way to capture their strength is to look at the proportion of campaign donations in a given jurisdiction from teachers’ unions.14 Another way is to use information from local or state teachers’ unions’ tax forms to capture the amount of teachers’ union revenue and expenditures per teacher and the size of teachers’ union membership relative to the number of teachers in a jurisdiction.15 Some researchers have used a combination of all these measures, along with surveys of policymakers, to create an index of teachers’ union strength.16
One of the challenges in studying the impact of teachers’ unions and collective bargaining based on marginal changes in teachers’ union/CBA strength is that unions and bargaining negotiations are not randomly assigned to school districts. Instead, teachers’ unions tend to organize and negotiate in locations where working conditions are more challenging and where student achievement is lower (because these are the locations where teachers may believe that unions add the most value).17 Consequently, simple comparisons between unionized and nonunionized districts or between districts with stronger teachers’ unions and those with weaker teachers’ unions likely reflect these demographic or contextual differences, rather than the impact of unionization or union strength. For instance, simple analyses that compare unionized to nonunionized districts often find that students in unionized school districts perform worse than students in nonunionized districts. This difference in student performance may have little relationship to actual union activity and may simply be spuriously related to the conditions that make unionization more or less likely.
Researchers have used various approaches to overcome this challenge, including:
The Timing of Union Certification. The first approach involves adding a time dimension to the analysis. Although whether a school district is unionized is correlated with school district characteristics, this approach assumes that the timing of unionization is less or not at all correlated with key outcome variables.18 One challenge with this approach is that most unions in the United States were certified decades ago, limiting researchers’ ability to explore the impact of unionization on more recent outcomes. However, some researchers have begun to examine charter school unionization, as the certification of charter school teachers’ unions has been more recent.19
Exploiting Policy Shocks to Union Strength. The second approach is to use the timing of external policy shocks that amplify or diminish the power of teachers’ unions. Under this approach, individual policy changes may be correlated with union strength and key outcomes, but the timing of policy changes are plausibly random. For example, researchers have explored how important outcomes, such as student achievement, change when teachers’ union power was substantially diminished by the enactment of right-to-work policies, which prohibited teachers’ unions from collecting fees as a condition of collective bargaining representation.20 Researchers have also used the timing of collective bargaining negotiations relative to school finance reforms or tax referendums to answer questions about union power and school district expenditures.21 Furthermore, studies have examined how student outcomes and teacher labor markets change in states that have greatly reduced teachers’ collective bargaining rights.22
Key finding #1: Teachers’ union advocacy in school board elections and on school district policy can make a difference in school district policy decisions.
While discussions of teachers’ unions often focus on their impacts on students and teachers, most of these impacts occur because of these unions’ influence on education policy at the local, state, and federal levels. Scholars have noted that local and state control over education policy favors teachers’ unions.23 School board elections typically have low voter turnout, providing highly organized local unions the opportunity to shape who governs school districts and who ratifies their CBAs.24 At the state level, there are few education-focused interest groups that are as organized as teachers’ unions are. State-level teachers’ unions lobby to encourage the enactment of policies that they believe will make schools better (and grow union power and influence) and to discourage the enactment of policies that they believe will make schools worse (and weaken union power and influence).25
At the local level, school boards consisting of teachers’ unions’ favored candidates and former educators are more likely to adopt union-friendly CBAs.26 Hence, unsurprisingly, teachers’ unions make considerable efforts to influence school board elections, and as a result of that support, union-endorsed candidates do very well. Union endorsement significantly increases the likelihood of a school board member winning an election, even when candidate quality is controlled for.27 Voter exposure to information about a candidate’s teachers’ union endorsement increases support by 6–8 percentage points. Voters believe union-endorsed candidates would improve student achievement and unions tend to endorse incumbents who raise teacher pay.28 From 1995 to 2020, union-endorsed candidates in California won 71% of their races. In Florida, 63% of union-endorsed candidates between 2010 and 2020 won their races. 29
The COVID-19 pandemic provided an opportunity to test how influential teachers’ unions were in local education policymaking. The initial decisions to close schools for in-person learning during the spring 2020 semester were largely left to state governors.30 However, the decisions to keep schools closed for in-person learning during fall 2020 and subsequent semesters were largely left to local school boards. School districts with stronger unions were much less likely to open for in-person instruction during the fall 2020 semester.31
A number of studies have explored how teachers’ unions are shaped by state education policies. For example, the growth in laws during the 1970s and 1980s that gave teachers’ unions the right to bargain on behalf of teachers drastically increased teachers’ union membership.32 In contrast, relatively recent enactments of right-to-work laws, which bar the requirement that teachers join a union as a condition of employment or pay a fair share fee, decreased teachers’ union membership by approximately 40% of the average membership count.33
Relatively few studies have focused on how teachers’ unions shape state education policies. One study examined teacher policies proposed and enacted across five legislative cycles, coding them based on whether they strengthened or weakened union rights. The researchers found that fewer favorable laws were proposed in areas where teachers’ unions spent more on elections and lobbying than school choice advocacy groups or business groups spent.34 Another study found similar results when examining specific education policies, such as those governing public school choice, teacher evaluation, and teacher pay. States with a higher proportion of campaign contributions from teachers’ unions were less likely to adopt reform-oriented policies in these areas.35
Even fewer studies have explored how teachers’ unions shape federal politics. The limited research available suggests that the largest national teachers’ union, the NEA, spends millions of dollars on federal elections and that the candidates whom it supports win more often than they lose.36 While the flow of NEA campaign contributions to Democratic candidates in federal elections is significant, there is evidence that the NEA also has several allied Republican lawmakers, particularly in states that lean Democratic. During a six-year span (2010–2016), the NEA took an official position on 148 pieces of federal legislation, and final legislative votes aligned with their position 79% of the time.
Key finding #2: School districts with stronger unions and stronger CBAs spend more per student on education.
One argument in favor of teachers’ unions and collective bargaining is that teachers’ unions demand more resources for schools and students and direct expenditures in productive ways based on the insights of their membership. However, opponents of teachers’ unions argue that teachers’ unions unnecessarily drive up schooling costs and direct funding in ways that primarily benefit union membership, not students.
According to the best evidence, it is generally the case that school districts with the strongest unions and the most comprehensive CBAs spend more per student and spend differently than school districts with weaker or nonexistent unions or no collective bargaining rights. For example, when school districts unionize following the passage of laws granting the right to teacher collective bargaining, their expenditures increase by 12.3%.37 School districts also spend more as the restrictiveness or strength of teacher CBAs increases. A 1 s.d. increase in CBA strength is associated with a 1.2% increase in school district expenditures, which equates to approximately $111 more per pupil for the typical school district.38 Furthermore, the spending increases associated with CBA strength are not spread evenly across categories in school district budgets. Most of the increases associated with CBA strength are in expenditures on instruction (approximately $73 more per pupil per 1 s.d. increase in CBA strength) and instructional support (approximately $20 more per pupil per 1 s.d. increase in CBA strength).
When school districts receive new revenue, expenditures on education rise more in areas with stronger teachers’ unions than in areas with weaker teachers’ unions.39 When new state school revenue comes in, school districts may reduce their local tax effort (sometimes called crowding out or supplanting), or they may grow their strategic budget reserves by not spending these funds. In terms of crowding out, prior research finds that when receiving new revenue, districts in states with stronger teachers’ unions maintain their local tax effort to a far greater degree than school districts in states with weak teachers’ unions. In terms of spending, prior research also finds that the average school district spent 50 cents for every 1$ increase in new state revenue. However, school districts in states with teachers’ unions that were 1 s.d. stronger spent 69 cents for every 1$ increase in new state revenue. Additional research finds that when teachers’ unions and school districts are negotiating new CBAs immediately after the approval of an increase in new local tax revenue for schools, they spend $50 more per pupil on teacher benefits and reduce their reserve funds by an average of 6.8 percentage points (p.p.) compared to school districts that are not in bargaining negotiations.40
Finally, school expenditures decrease when teachers’ unions are weakened by new legislation. Following the enactment of right-to-work laws, expenditures within school districts decreased by $800 per pupil in the decade following the enactment of these laws.41 Furthermore, when states enacted laws such as Wisconsin’s Act 10 that diminished the scope of collective bargaining over teacher salaries and benefits, school district expenditures decreased by 3.8%.42
Key finding #3: Teachers’ unions raise teacher salaries.
Enhanced working conditions are frequently cited as the primary advantage of unionization in education.43 According to this perspective, teachers’ unions emerged in public education to address the deficiencies of the centralized, bureaucratic, and management-dominated school systems of the early 20th century. During that period, teachers individually faced inadequate compensation and were vulnerable to managerial and administrative abuses. Again, opponents argue that teachers’ unions drive up spending on working conditions to inefficient and unproductive levels, leading to higher costs for school districts and lower student achievement.
The preponderance of evidence suggests a positive relationship between teachers’ unions and teacher salaries. One study shows that teacher salaries increase by between 4% and 12% with the onset of unionization or collective bargaining44 and decrease by 8% when teachers’ unions and collective bargaining are substantially reduced.45 In school districts with strong teachers’ unions, teacher salaries increase by 84 cents for every 1$ increase in state revenue, compared to just 32 cents for every 1$ increase in state revenue in school districts where the power of teachers’ union is average.46 When new revenue comes to school districts from reforms to school finance systems, teacher salaries increase by $4,730 in states with strong teachers’ unions, compared to little to no change in the salaries of teachers in states with weaker teachers’ unions.47 In other words, strong teachers’ unions successfully channel new revenue for schools to teacher salaries.
Teachers’ unions have a strong preference for allocating higher salary increases to veteran teachers.48 Some studies have found that union activity increases the salaries of experienced teachers by as much as 28%, with no change in the salaries of novice teachers.49 This is less the case in areas where teachers’ unions are weakened. In the case of Act 10, after existing CBAs expired, pay schemes began to move away from allocating based on seniority to allocating based on flexible and more individualized negotiations with teachers. As a result, higher-quality teachers received higher pay. Teachers in Wisconsin received a 0.4% higher salary per 1 s.d. increase in teaching quality.50
Teachers’ unions also help narrow gender pay gaps. In school districts with traditional collective bargaining, the gender pay gap is $790 smaller than in school districts without collective bargaining.51 The gender pay gap among teachers increased in Wisconsin following the introduction of flexible pay arrangements, mainly because female teachers were between 12% and 23% less likely than men to have experience negotiating pay.52
It is likely that CBAs meaningfully affect working conditions beyond salaries, but very little research has explored the relationship between collective bargaining and improvements in other working conditions. Most research that has done so focuses narrowly on classroom time and class sizes. Prior research finds that unionization/collective bargaining is associated with a decrease in the hours that teachers spend in the classroom.53 The effect on class sizes is less clear. Some research finds that unionization and bargaining are associated with a decrease in class sizes.54 However, other studies find that unions are regularly willing to trade higher class sizes for improved teacher salaries, as mentioned above.55 This finding is consistent with surveys that find that teachers are willing to have larger class sizes in exchange for higher salaries.56
Key finding #4: Teacher turnover is lower where teachers’ unions are stronger, and it increases in areas where union rights and collective bargaining are restricted
Consistent with the idea that when employees can utilize their voice, they are less likely to exit jobs, research suggests that teachers’ unions and collective bargaining reduce teacher turnover. Teachers are less likely to turn over in areas where unions are stronger. For every 10% increase in the density of unions, experienced and novice teachers are 4–7% less likely to quit.57 Multiple researchers have also explored what happens to teacher turnover when teachers’ unions are weakened. Following the enactment of Act 10 in Wisconsin, teacher turnover increased by approximately 1 p.p. per year.58 Retirements also increased by 18 p.p. among those aged 55 and older in the year after Act 10 enactment.59 Additionally, higher-quality teachers sought out school districts that used flexible pay schemes that paid more for additional student learning, while lower-quality teachers sought out school districts that still used the more traditional step-and-column salary schedule.60 Furthermore, Act 10 led to an increase in teaching degrees at Wisconsin institutions by 1.5 p.p., or about 20 additional degrees per institution, with these teaching candidates increasingly coming from more selective institutions with average ACT scores of 1 s.d. or more above the mean.61 The reason may be that higher-quality teacher candidates could make money more under the flexible pay reforms.
Key finding #5: Most often, teachers’ unions have no impact or a slight negative impact on performance.
Small increases in union strength have no impact on student performance. For example, marginal increases in the strength or restrictiveness (the degree to which a given CBA limits school and school district leaders in administering schools) of CBAs have no impact on student achievement.62 However, larger changes in union power can make a difference in student outcomes. When teachers’ unions are substantially weakened by state policies, short-run student achievement declines or does not change. In the case of Wisconsin’s Act 10, short-run achievement decreased by 0.20 s.d., primarily at low-performing schools.63 Right-to-work policies, which removed the ability of teachers’ unions to charge nonunion members for collective bargaining representation, resulted in no change in student outcomes.64
The long-term impacts of teachers’ unions on students may be negative, but more research in this area needs to be conducted. One study explored the impact of the passage of laws requiring that school districts negotiate CBAs with teachers’ unions (which mainly occurred between 1960 and 1987) on later-life earnings. The study found that students exposed to 10 years of collective bargaining law from kindergarten to 12th grade experienced a decrease in annual earnings of $2,134 (3.93%) and a decrease in the number of weekly hours worked of 0.42 hours at ages 35 through 49.65 Additionally, exposure to such laws led to a 1 p.p. decrease in the likelihood of employment, a 0.8 p.p. decrease in the likelihood of labor force participation, and an increase in the likelihood of sorting into a low-skill occupation. These effects were found among men but not women. Exposure to bargaining laws did not significantly decrease years of schooling, which is surprising given the impacts on labor market outcomes. The authors interpreted the effects as evidence that collective bargaining decreased the quality of education—at least for men—such that students had fewer skills, particularly noncognitive skills, in adolescence and early adulthood that would make them successful in the labor market. Other research has examined the longer-term impacts of policies such as Act 10 that weakened teachers’ union power. Act 10 gave school districts the opportunity to adopt flexible pay schedules that compensated teachers for student performance gains. Districts that adopted such schedules experienced an influx of higher-quality teachers. This influx was associated with a 0.06 s.d. increase in math performance and a 0.04 s.d. increase in reading performance.66
There may be one context in which teachers’ union power improves student performance: increases in historic state spending on education. During the historic court-ordered school finance reforms of the 1970s and 1980s, states sent additional funds to school districts, particularly those serving students from economically disadvantaged backgrounds.67 Recall from the discussion on the impact of teachers’ unions on school expenditures that school districts with stronger teachers’ unions maintain their local tax effort to a far greater degree than do school districts in states with weak teachers’ unions when receiving new state revenue from school finance reforms. The maintenance of this local tax effort, coupled with the new state revenue as a result of union involvement, translates into academic benefits for students. After school finance reforms, student achievement in school districts where the power of state teachers’ union was average increased by 0.009 s.d. per year, whereas student achievement increased by 0.013 s.d. per year in school districts with strong teachers’ unions.68 Furthermore, the effect of strong teachers’ unions on achievement was particularly concentrated in low-income school districts after the reforms. Low-income school districts in states with strong unions saw an increase in achievement of 0.16 s.d. per year, compared to 0.08 s.d. per year in low-income districts with weak teachers’ unions and no significant change in achievement in high-income school districts with weak and strong unions. These outcomes can be taken as evidence that strong teachers’ unions, by striving to maximize the welfare of their members, make large school finance reforms more effective in raising student achievement. They do so by ensuring that new state school funding does not supplant but, rather, supplements local school funding.
When examining collective bargaining specifically, research suggests that the effects of CBAs on student achievement are not uniform across all areas of the contract or for all students. For example, researchers have found that increases in the restrictiveness of CBA class size provisions were associated with decreases in student achievement gaps, while increases in the restrictiveness of CBA teacher evaluation and teacher leave policies were associated with increases in these gaps. These effects were small in magnitude (between 0.02 s.d. and 0.05 s.d.), were mainly in math, and primarily affected low-income students, as opposed to high-income students.69 Hence, the equity implications of CBAs are not considerably positive or negative. However, if the actors who are negotiating contracts are looking for ways to address the small negative impact of contract language on students from economically disadvantaged backgrounds, they may look to renegotiate common CBA evaluation systems, such as those built primarily on administrator observations of teachers. These systems tend to strain the capacity of school principals and do little to improve student performance and narrow student achievement gaps.70
Finally, there is some evidence that increases in teachers’ union strength are associated with lower school district efficiency in improving student performance. Researchers have measured this outcome by creating school efficiency ratios that divide student achievement proficiency rates by school district expenditures. This research finds that 1 s.d. increase in contract restrictiveness is associated with a decrease in school district efficiency of 1.3–2.4% (i.e., 0.03–0.05 s.d.).71 In other words, as the strength of school districts’ CBAs increase, they must spend 1.3–2.4% more (i.e., approximately $200 per pupil), on average, to achieve the same level of student performance. In another study, researchers found that school districts that allocated new revenue from tax referendums prior to their next bargaining cycle spent less on teacher salaries and benefits, hired more teachers, and experienced an extra 0.002 s.d. increase in student achievement for every $1,000 in annual per-pupil expenditures compared to school districts that collectively bargained around when the new revenue came in. In other words, school districts that negotiate with teachers’ unions when new revenue is available spend differently and less efficiently than do those that do not.72
Policymakers, practitioners, and scholars continue to debate the role of teachers’ unions in public education in the United States and their impact. Although policies governing teachers’ unions have shifted significantly over the last decade—due to changes to collective bargaining rules and a Supreme Court ruling that limits the ability of public-sector unions to collect fees for union services—teachers’ unions are still visible in multiple facets of the education system. As highly organized interest groups, they shape federal, state, and local elections, where their endorsed candidates win more often than they lose. They actively negotiate CBAs with school district administrations in 44 states. They organize teachers for collective action, and the number of strikes and walkouts by teachers’ unions has increased in recent years.73
Whether the education system would be better off in the absence of teachers’ unions is difficult to determine. During the historic school finance reforms of the 1970s and 1980s, teachers’ unions helped drive educational spending in ways that were productive for students. More recently, however, increases in the strength of CBAs have yielded higher school expenditures but no changes in student performance. Where teachers’ unions have been substantially weakened through restrictions on collective bargaining, school expenditures decreased, and student achievement declined in the short run but increased in the long run. Additionally, in states that have made changes to other union-related laws, such as the ability of teachers’ unions to collect membership dues (i.e., right-to-work laws), student achievement did not measurably change, but school expenditures declined.
Ultimately, the current state of research points to some concerns about the impact of teachers’ unions on the efficiency of the education system, consistent with the rent-seeking perspective. There is evidence that teachers’ unions, at least more recently, have channeled educational expenditures that, if used in other ways, would be more effective in improving student achievement. It follows, then, that further restricting the influence of teachers’ unions, for example, by narrowing the scope of collective bargaining to fewer issues, may make school spending more efficient. However, imposing such restrictions will likely come at the cost of greater teacher turnover, at least in the short term.
Areas for future research
While the rent-seeking and voice perspectives provide helpful lenses through which to understand teachers’ unions and their impact on education, some have recently critiqued these viewpoints for their “industry-specific” conception of teachers’ unions. That is, the perspectives are primarily focused on what unions do within the education sector and are less concerned with the impact of teachers’ unions on the advancement of middle- and working-class interests, more broadly.74 For example, more teachers’ unions in the United States are organizing for the “common good” and are making demands related to broader issues of social justice, such as affordable housing, healthcare and racial justice.75 Are these rent-seeking/voice behaviors, or are they something entirely different? This area of research is currently limited to a few case studies, some of which are outside of the United States. Broadening the conceptualization of teachers’ unions in new research is important for a few reasons. First, doing so will more fully capture the impact of teachers’ unions beyond the education-specific effects currently measured in the literature. For example, researchers might explore the impact of teachers’ union power on income and racial inequality. Second, doing so will help highlight union activities beyond local-level collective bargaining, on which most of the current literature focuses. For example, researchers might highlight the extent to which teachers’ unions build progressive coalitions in state legislatures to influence policies outside of education.
More work can also be done within education to understand the contexts in which teachers’ unions enhance student achievement versus the contexts in which they harm student achievement. For example, as mentioned above, in the context of state school finance reforms, teachers’ unions appear to facilitate improvements in student achievement by helping maintain local investments in education. However, when school districts and teachers’ unions negotiate over local tax revenue as a result of a passed tax referendum, they experience lower returns to student achievement than when not negotiating. Are there certain thresholds of teachers’ union power where, if fallen short of or exceeded, the influence of teachers’ unions becomes less efficient for driving educational improvement? Are there specific areas of CBAs where, if removed/added to the scope of bargaining, educational outcomes will improve? This type of research will help policymakers and educational leaders better understand the contexts in which teachers’ unions help drive educational improvements versus the contexts where they do not.
National Education Association and American Federation of Teachers. 2023. Form LM-2 Labor Organization Annual Report.↩︎
Murphy, Marjorie. 1990. Blackboard Unions: The AFT and the NEA, 1900–1980. Ithaca, NY: Cornell University Press. Vol. 124.↩︎
National Council on Teacher Quality. 2019. Collective Bargaining Laws. https://www.nctq.org/contract-database/collectiveBargaining.↩︎
Marianno, Bradley D., Tara Kilbride, Roddy Theobald, Katharine O. Strunk, Joshua M. Cowen, and Dan Goldhaber. 2018. Cut from the Same Cloth? Comparing Urban District CBAs within States and across the United States. Educational Policy 32(2): 334–359.↩︎
Han, Eunice S., and Jeffrey Keefe. 2023. What Teachers’ Unions Do for Teachers When Collective Bargaining is Prohibited. Labor Studies Journal 48(2): 183–212.↩︎
Open Secrets. Organization Profiles. Retrieved from https://www.opensecrets.org/orgs/all-profiles.↩︎
Lyon, Melissa Arnold. 2023. Current Perspectives on Teacher Unionization, and What They’re Missing. Educational Policy 37(5): 1420–1443.↩︎
Hoxby, Caroline M. 1996. How Teachers' Unions Affect Education Production. The Quarterly Journal of Economics 111(3): 671–718.↩︎
The difference between the optimal allocation of resources and the allocation achieved due to the advocacy of teachers’ unions represents a rent for unions and an inefficiency in the school system.↩︎
Cowen, Joshua M., and Katharine O. Strunk. 2015. The Impact of Teachers’ Unions on Educational Outcomes: What We Know and What We Need to Learn. Economics of Education Review 48: 208–223.↩︎
Strunk, Katharine O., and Jason A. Grissom. 2010. Do Strong Unions Shape District Policies? Collective Bargaining, Teacher Contract Restrictiveness, and the Political Power of Teachers’ Unions. Educational Evaluation and Policy Analysis 32(3): 389–406.↩︎
Strunk, Katharine O., and Sean F. Reardon. 2010. Measuring the Strength of Teachers' Unions: An Empirical Application of the Partial Independence Item Response Approach. Journal of Educational and Behavioral Statistics 35(6): 629–670.↩︎
Strunk, Katharine O., Joshua Cowen, Dan Goldhaber, Bradley D. Marianno, Roddy Theobald, and Tara Kilbride. 2022. Public School Teacher Contracts and State-Level Reforms: Assessing Changes to Collective Bargaining Restrictiveness across Three States. American Educational Research Journal 59(3): 538–573; Marianno, Bradley D., David S. Woo, and Kate Kennedy. 2023. Collective Bargaining Agreement Restrictiveness in Unionized Charter Schools. Educational Policy: 08959048231178024; Marianno, Bradley D., and Annie A. Hemphill. 2023. Pandemic Memoranda: How School District and Teachers' Union Administrators Modified Collective Bargaining Agreements during the COVID-19 Pandemic. Journal of Educational Administration 61(6): 604–622.↩︎
Hartney, Michael, and Patrick Flavin. 2011. From the Schoolhouse to the Statehouse: Teacher Union Political Activism and US State Education Reform Policy. State Politics & Policy Quarterly 11(3): 251–268; Marianno, Bradley D. 2020. Compared to What? Changes in Interest Group Resources and the Proposal and Adoption of State Teacher Policy. Policy Studies Journal 48(4): 982–1022.↩︎
Northern, Amber M., Janie Scull, and Dara Zeehandelaar. 2012. How Strong Are US Teacher Unions? A State-by-State Comparison. Thomas B. Fordham Institute. Retrieved February 18 (2012): 2018.↩︎
Marianno, Bradley D., and Katharine O. Strunk. 2018. The Bad End of the Bargain?: Revisiting the Relationship between Collective Bargaining Agreements and Student Achievement. Economics of Education Review 65: 93–106.↩︎
Lovenheim, Michael F. 2009. The Effect of Teachers’ Unions on Education Production: Evidence from Union Election Certifications in Three Midwestern States. Journal of Labor Economics 27: 525–587.↩︎
Matsudaira, Jordan D., and Richard W. Patterson. 2017. Teachers’ Unions and School Performance: Evidence from California Charter Schools. Economics of Education Review 61: 35–50.↩︎
Lyon, Melissa A. 2023a. The Effect of Right to Work Laws on Union Membership and School Resources: Evidence from 1942–2017. Educational Researcher 52(6): 339–347.↩︎
Brunner, Eric, Joshua Hyman, and Andrew Ju. 2020. School Finance Reforms, Teachers' Unions, and the Allocation of School Resources. Review of Economics and Statistics 102(3): 473–489.↩︎
Baron, Jason E. 2018. The Effect of Teachers’ Unions on Student Achievement in the Short Run: Evidence from Wisconsin’s Act 10. Economics of Education Review 67: 40–57.↩︎
Hartney, Michael T. 2022. How Policies Make Interest Groups: Governments, Unions, and American Education. Chicago, IL: University of Chicago Press.↩︎
Moe, Terry M. 2006. The Union Label on the Ballot Box: How School Employees Help Choose Their Bosses. Education Next 6(3): 58–67.↩︎
Moe, Terry M. 2011. Special Interest: Teachers Unions and America’s Public Schools. Washington, D.C.: Brookings Institution Press.↩︎
Hartney, Michael T. 2023. Teachers’ Unions and School Board Elections: A Reassessment. In Interest Groups in US Local Politics. Edited by Sarah Anzia. Cham: Springer Nature Switzerland. 59–84.↩︎
Hartney, Michael. T., & Kogan, Vladimir. (2025). The politics of teachers' union endorsements. American Journal of Political Science, 69(3), 1163-1179.↩︎
Hartney (2023).↩︎
Grossmann, Matt, Sarah Reckhow, Katharine O. Strunk, and Meg Turner. 2021. All States Close But Red Districts Reopen: The Politics of In-Person Schooling during the COVID-19 Pandemic. Educational Researcher 50(9): 637–648.↩︎
Marianno, Bradley D., Annie A. Hemphill, Ana Paula S. Loures-Elias, Libna Garcia, Deanna Cooper, and Emily Coombes. 2022. Power in a Pandemic: Teachers’ Unions and Their Responses to School Reopening. AERA Open 8: 23328584221074337; Hartney, Michael T., and Leslie K. Finger. 2022. Politics, Markets, and Pandemics: Public Education’s Response to COVID-19. Perspectives on Politics 20(2): 457–473; Grossmann et al. (2021); Harris, Douglas N., and Daniel M. Oliver. 2021. Why Did So Many Public Schools Stay Remote during the COVID Crisis? Policy Brief. National Center for Research on Education Access and Choice.↩︎
Lyon, Melissa A. 2021. Heroes, Villains, or Something in Between? How “Right to Work” Policies Affect Teachers, Students, and Education Policymaking. Economics of Education Review 82: 102105.↩︎
Marianno, Bradley D. 2018. Down But Not Out: The National Education Association in Federal Politics. Educational Policy 32(2): 234–254.↩︎
Marianno, Bradley D., Paul Bruno, and Kathrine O. Strunk. 2021. The Effect of Teachers’ Union Contracts on School District Efficiency: Longitudinal Evidence from California. Sage Open 11(1): 2158244020988684; Strunk, Katharine O. 2011. Are Teachers' Unions Really to Blame? Collective Bargaining Agreements and Their Relationships with District Resource Allocation and Student Performance in California. Education Finance and Policy 6(3): 354–398; Eberts, Randall W. 1983. How Unions Affect Management Decisions: Evidence from Public Schools. Journal of Labor Research 4(3): 239–247; Eberts, Randall W., and Joe A. Stone. 1984. Unions and Public Schools: The Effect of Collective Bargaining on American Education. Lexington, MA: Lexington Books.↩︎
Cook, Jason, Stéphane Lavertu, and Corbin Miller. 2021. Rent-Seeking through Collective Bargaining: Teachers Unions and Education Production. Economics of Education Review 85: 102193.↩︎
Han, Eunice S., and Emma Garcia. 2024. The Effect of Changes in Legal Institutions Weakening Teachers’ Unions on Districts’ Spending on Teacher Compensation. American Journal of Education 130(2): 000-000.↩︎
Bascia, Nina. 2009. Teachers as Professionals: Salaries, Benefits and Unions. International Handbook of Research on Teachers and Teaching: 481–489.↩︎
Hoxby’s (1996) difference-and-differences and instrumental variables (IV) estimates suggest that teacher salaries in unionized districts are 5% higher, on average, than those in nonunionized districts. West and Mykerezi (2011) provide similar estimates through their IV approach, finding that the presence of a CBA is associated with a 3.9% increase in average teacher salaries. Baugh and Stone (1982) explicitly evaluate the influence of teachers’ unions on salary levels by estimating cross-sectional wage-level and wage change regressions on a national sample of teacher data. They find that the estimated premium for joining a union was 12% in the 1977–1978 school year (up from 4% in the 1974–1975 school year). Brunner and Squires (2013) employ a fixed-effects approach that controls for time-invariant unobserved sources of omitted variable bias but may not fully account for all time-varying impacts, and they find that teachers’ unions increase overall teacher salary levels by 4.5%.↩︎
Baron (2018); Litten, Andrew. 2016. The Effects of Public Unions on Compensation: Evidence from Wisconsin. Unpublished paper.↩︎
Nguyen, Tuan D., J. Cameron Anglum, and Michael Crouch. 2023. The Effects of School Finance Reforms on Teacher Salary and Turnover: Evidence from National Data. AERA Open 9: 23328584231174447.↩︎
Grissom, Jason A., and Katharine O. Strunk. 2012. How Should School Districts Shape Teacher Salary Schedules? Linking School Performance to Pay Structure in Traditional Compensation Schemes. Educational Policy 26(5): 663–695.↩︎
Winters, John V. 2011. Teacher Salaries and Teacher Unions: A Spatial Econometric Approach. ILR Review 64(4): 747–764; Brunner, Eric J., and Tim Squires. 2013. The Bargaining Power of Teachers’ Unions and the Allocation of School Resources. Journal of Urban Economics 76: 15–27; Rose, Heather, and Jon Sonstelie. 2010. School Board Politics, School District Size, and the Bargaining Power of Teachers’ Unions. Journal of Urban Economics 67(3): 438–450.↩︎
Biasi, Barbara. 2021. The Labor Market for Teachers under Different Pay Schemes. American Economic Journal: Economic Policy 13(3): 63–102.↩︎
Han, Eunice S. 2020. The Effects of Teachers’ Unions on the Gender Pay Gap among US Public School Teachers. Industrial Relations: A Journal of Economy and Society 59(4): 563–603.↩︎
Biasi, Barbara, and Heather Sarsons. 2022. Flexible Wages, Bargaining, and the Gender Gap. The Quarterly Journal of Economics 137(1): 215–266.↩︎
Eberts, Randall W. 1984. Union Effects on Teacher Productivity. ILR Review 37(3): 346–358; Zigarelli, Michael A. 1996. Dispute Resolution Mechanisms and Teacher Bargaining Outcomes. Journal of Labor Research 17(1): 135–148.↩︎
Brunner and Squires (2013); Hall, Clayton W., and Norman E. Carroll. 1973. The Effect of Teachers' Organizations on Salaries and Class Size. ILR Review 26(2): 834–841; Rose and Sonstelie (2010); Woodbury, Stephen A. 1985. The Scope of Bargaining and Bargaining Outcomes in the Public Schools. ILR Review 38(2): 195–210.↩︎
Goldhaber, Dan, Michael DeArmond, and Scott DeBurgomaster. 2011. Teacher Attitudes about Compensation Reform: Implications for Reform Implementation. ILR Review 64(3): 441–463.↩︎
Han, Eunice S. 2020. The Myth of Unions’ Overprotection of Bad Teachers: Evidence from the District–Teacher Matched Data on Teacher Turnover. Industrial Relations: A Journal of Economy and Society 59(2): 316–352.↩︎
Roth, Jonathan. 2017. Union Reform and Teacher Turnover: Evidence from Wisconsin’s Act 10. Harvard Kennedy School.↩︎
Baron, Jason E. 2021. Union Reform, Performance Pay, and New Teacher Supply: Evidence from Wisconsin's Act 10. AEA Papers and Proceedings 111: 445–449.↩︎
Lovenheim, Michael F., and Alexander Willén. 2019. The Long-Run Effects of Teacher Collective Bargaining. American Economic Journal: Economic Policy 11(3): 292–324.↩︎
Jackson, C. Kirabo, Rucker Johnson, and Claudia Persico. 2014. The Effect of School Finance Reforms on the Distribution of Spending, Academic Achievement, and Adult Outcomes (No. w20118). National Bureau of Economic Research, 2014.↩︎
Marianno, Bradley D. 2021. A Negotiated Disadvantage? California Collective Bargaining Agreements and Achievement Gaps. Educational Researcher 50(7): 451–462.↩︎
Bleiberg, Joshua, Eric Brunner, Erica Harbatkin, Matthew A. Kraft, and Matthew G. Springer. 2023. Taking Teacher Evaluation to Scale: The Effect of State Reforms on Achievement and Attainment (No. w30995). National Bureau of Economic Research.↩︎
Lyon, Melissa Arnold, Matthew A. Kraft, and Matthew P. Steinberg. 2024. The Causes and Consequences of US Teacher Strikes (No. w32862). National Bureau of Economic Research.↩︎
McCartin, Joseph A., Marilyn Sneiderman, and Maurice BP-Weeks. 2020. Combustible Convergence: Bargaining for the Common Good and the #RedforEd Uprisings of 2018. Labor Studies Journal 45(1): 97–113.
Marianno, Bradley D. (2025). "Teachers' Unions and Collective Bargaining," in Live Handbook of Education Policy Research, in Douglas Harris (ed.), Association for Education Finance and Policy, viewed 03/10/2026, https://livehandbook.org/k-12-education/workforce-teachers/unions-and-collective-bargaining/.