The earliest call for formal teacher entry requirements in US public schools dates to the 1960s, following a concerning downward trend in student test scores. Proponents believe that a minimum standard for public school teachers enhances student learning. After decades of development, teacher licensure has become the primary system to ensure teacher quality in US public schools, and public school teachers have become the largest licensed profession in the nation. Although teacher licensing is universal in the US public sector, state legislatures determine the requirements, which have varied substantially across jurisdictions.

The complex historical development of teacher licensure and a lack of concurrent national data create challenges to evaluating the impacts of licensure exams on teachers and students. Thus, the overall effect of licensure exams is unknown. On the one hand, they increase entry costs that reduce teacher availability and may distort school investments. On the other hand, a minimum standard for teachers may improve student learning by enhancing teachers’ skills and eliminating incompetent teachers. Since 2014, the Educative Teacher Performance Assessment (edTPA), a performance-based exam to evaluate prospective teachers’ readiness, has gained popularity nationwide. By 2018, the edTPA had become a mandatory component of initial teacher licensure in eight states.

The edTPA offers two novel features compared with existing written licensure tests. Unlike traditional one-time tests, the edTPA is a semester-long project involving lesson plans, classroom videos, and follow-up reports. The extra money and time required create an additional barrier to entry, potentially exacerbating existing teacher shortages. The edTPA uses a performance-based format meant to resemble the delivery of instruction. It has been a revolutionary development in the education community since the 2010s to establish a more practical way to evaluate teaching readiness.

Our research uses a national sample of teachers and students to study the effect of the edTPA on the number of teachers and on students’ standardized test scores. The fact that states adopted the edTPA at different times provides a means to study its effectiveness; this allowed us to compare outcomes in states that used the edTPA with outcomes in other states before and after the exam’s implementation.

Our research first examines the number of graduates from teacher preparation programs—an important source of new teachers in US public schools—documented in the Integrated Postsecondary Education Data System. Our findings show that between 2011 and 2019, the edTPA reduced teacher graduates by 9.15–11.3 percent. This negative effect primarily occurred in undergraduate programs, less selective universities, and minority-concentrated universities, suggesting that the edTPA may pose equity concerns.

Our research then assesses the impact of the edTPA on student test scores from 2009 to 2019 on the National Assessment of Educational Progress. This test is the largest nationally representative assessment of core subjects and provides a common yardstick for comparing student progress in different states. The dataset links students to the years of experience of their teachers, enabling us to determine the test scores of new teachers’ students. Moreover, a teacher’s state and their years of experience allowed us to measure whether they took the edTPA. The exam could influence student test scores in two ways: directly, if their own teacher took the exam and improved their teaching; or indirectly, through changes in the composition of teachers at a school. Our findings show no evidence that the implementation of the edTPA improved student test scores. This null effect aligns with prior research indicating that performance on licensure exams does not reliably predict classroom effectiveness.

In addition, our findings suggest that novice teachers who completed the edTPA reported lower subjective preparedness to teach, consistent with qualitative studies suggesting that the exam may distract candidates from more practical learning during their internships. Finally, some school districts hired teachers with temporary licenses to address staffing shortages potentially exacerbated by barriers to entry related to the edTPA.

Our analysis contributes to the ongoing debate about expanding or revoking the edTPA, including its implications for the teacher shortage. Although our findings are limited to the exam’s short-run impacts, the causal relationships they reveal can inform policymakers addressing immediate challenges and considering proposals to change licensure standards in the US public school system.

Note
This research brief is based on Bobby W. Chung and Jian Zou, “Occupational Licensing in US Public Schools: Nationwide Implementation of Teacher Performance,” Journal of Public Economics 244 (April 2025).