Teacher sorting and the opportunity gap: a cross-national investigation of institutional differentiation and educational equity

Abstract

Inequitable access to teacher competence (‘teacher sorting’ or the teacher ‘opportunity gap’) is increasingly the focus of international educational bodies worldwide but is still relatively underexplored empirically. The overarching purpose of this doctoral thesis is to investigate the relationship between teacher sorting and educational inequity from a cross-national perspective, while empirically addressing theoretical questions related to social reproduction and inequality of educational opportunities in school systems. A final aim is to provide empirically grounded policy recommendations related to the findings. With these aims in mind, the constituent studies in the thesis cover several facets of the phenomenon of teacher sorting: the magnitude and development cross-nationally over the past two decades, the impact on inequity in student test scores, as well as the associated institutional features. The data come from international large-scale assessments such as the Trends in International Mathematics and Science Study (TIMSS, 1999-2019) and the Teaching and Learning International Survey (TALIS, 2018), and include 32 and 46 education systems, respectively, with a special focus on mathematics and science teachers. The main analytical approaches include descriptive statistical methods, panel data regressions with country fixed effects, and hierarchical generalized linear modelling. The dissertation is comprised of four empirical studies. Study I investigates the magnitude of teacher sorting cross-nationally as well as its development since 1999. Results show that the magnitude of inequity varies by the country and teacher qualification in focus. Few countries show widening inequities in the teacher qualification gaps. Study II investigates the impact of teacher sorting on mathematics achievement inequity and finds that more pronounced sorting by specialization exacerbates inequity in student achievement, and that this finding remains marginally significant after controlling for increasing socioeconomic school segregation. Studies III and IV investigate policy- and institution-level correlates of teacher sorting and teacher turnover, respectively. The results of Study III show a general pattern of mixed results related to stratification, accountability, autonomy, and competition, depending on the teacher quality indicator in focus. National economic development level as well as school competition were positively related to the slope on more than one occasion, however. Study IV found a more pronounced relationship between teacher turnover intentions and classroom SES in school systems with more widespread use of external accountability practices with student performance data. The results point to several key conclusions. First, there was evidence of inequity in teacher sorting across many educational systems to varying degrees. The patterns varied depending on how teacher qualifications and socioeconomic status were measured as well as how students were grouped. Next, the studies provided mixed results regarding school autonomy, accountability, competition and stratification, indicating that the determinants of socioeconomic teacher sorting do not easily generalize according to cross-national patterns. School competition was the single system-level variable to be associated with both qualifications. Despite this, performance data-based accountability (teacher appraisal) was consistently associated with higher turnover intention rates in low-SES settings. Appraisal of teacher performance for those working in lower-SES classrooms should rely on metrics other than performance data and should be conducted by those with appropriate knowledge of the school context. With respect to inequity in student outcomes, socioeconomic teacher sorting by specialization was found to have a modest effect. In most cases, priority should be given to democratizing access to teachers with appropriate content knowledge, but educational systems must go beyond providing socioeconomically disadvantaged students with teachers with basic qualification levels. While incentivizing the most competent teachers to work in socioeconomically disadvantaged settings is an ongoing challenge for many educational systems, building upon the content knowledge of underqualified mathematics teachers currently working in hard-to-staff settings is a worthwhile endeavor. Last, while reducing teacher sorting by specialization is likely to alleviate some degree of inequity in educational outcomes, it is not a panacea in the wider context of rising income inequality and social segregation in many educational systems.