Unequal access to competent teachers for children from different socioeconomic (SES) backgrounds may be one of the key factors contributing to the gap in performance between high- and low- SES groups internationally. Teacher quality has been identified as crucial for student achievement in mathematics (OECD, 2018; Darling-Hammond, 2000; Nye, Konstantopoulos, and Hedges, 2004; Blömeke and Delaney, 2012; Gustafsson and Nilsen, 2016). However, only a few articles within the international comparative research literature have analyzed the opportunity gap in access to qualified teachers and all have been cross-sectional thus far (Akiba, Letendre, and Scribner, 2007; Han, 2018). According to these articles, economically disadvantaged students often have teachers with fewer years of experience, lower educational attainment, and in some cases, a lack of training or specialization as compared to their more advantaged peers. International large-scale assessments (ILSAs) such as TIMSS are generally cross-sectional but have a longitudinal design at the country level (Gustafsson, 2013). Taking advantage of this feature, this paper aims to provide a longitudinal descriptive account of the distribution of teacher quality across 21 countries that participated in all TIMSS cycles from 2003-2015, underscoring variations in the equity of access to teacher quality over time. Based on Goe’s (2007) framework, teacher quality is conceptualized as subject matter specialization (mathematics), years of experience, level of educational attainment and formal teacher training, all of which are relatively comparable across cultures (Akiba et al., 2007). Measurement of the opportunity gap at the country level follows the method of Akiba et al. (2007), which compares the percentage of high- and low- SES students taught by qualified teachers. Preliminary results show that as an overall trend access to qualified teachers for low-SES students increased from 2003-2015. However, in a select few countries, the difference in percentage of high- and low-SES students taught by qualified teachers is growing. In addition to these results, the potential limitations of using ILSA data for country-level representation, the challenges related to determining meaningful change over time and comparing cross-country constructs of teacher quality will be discussed. Ultimately, this paper represents an important point of reference in exploring how the opportunity gap in access to qualified teachers has evolved over the past decade, along with setting up the possibility for causal inference related to inequitable educational outcomes in future research.

Akiba, M., LeTendre, G.K., & Scribner, J.P. (2007). Teacher quality, opportunity gap, and national achievement in 46 countries. Educational Researcher, 36, 369-387. Blömeke, S., & Delaney, S. (2012). Assessment of teacher knowledge across countries: a review of the state of research. ZMD Mathematics Education, 44, 223-247. Darling-Hammond, L. (2000). Teacher quality and student achievement: a review of state policy evidence. Educational Policy Analysis Archives, 8, 1-44. Goe, L. (2007). The link between teacher quality and student outcomes: A research synthesis. National Comprehensive Center for Teacher Quality, Washington, DC, USA. Retrieved from http://www.gtlcenter.org/sites/default/files/docs/LinkBetweenTQandStudentOutcomes.pdf Han, S.W. (2018). School-based teacher hiring and achievement inequality: a comparative perspective. International Journal of Educational Development, 61, 82-91. Gustafsson, J.E. (2013). Causal inference in educational effectiveness research: a comparison of three methods to investigate effects of homework on student achievement. School Effectiveness and School Improvement, 24, 275-295. Gustafsson, J.E., & Nilsen, T. (2016). Teacher quality, instruction quality and student outcomes. Springer. Nye, B., Konstantopoulos, S., & Hedges, L.V. (2004). How large are teacher effects? Educational Evaluation and Policy Analysis, 26, 237-257. Organization for Economic Co-operation and Development. (2018). Effective teacher policies. Insights from PISA. Paris: Author.