How can we evaluate the effectiveness of grammar schools in England? A regression discontinuity approach

Abstract

Previous research evaluating grammar school effectiveness has generally relied on snapshot or longitudinal regression models to deal with pre‐existing differences between grammar school pupils and those in non‐selective schools. These passive designs are based on correlations, and cannot demonstrate clear positive causal relationships between grammar school attendance and subsequent attainment. After accounting for the variables available for the analysis, pupils in different schools might still have distinct and unmeasured characteristics which threaten the validity of any conclusions drawn. Given that a randomised trial is not feasible under current conditions, this study addresses the limitations of previous research, using a regression discontinuity design (RDD) approach. This is the first use of RDD to attempt to make a robust causal inference about the effectiveness of grammar schools in one local authority in England. However, the authority, the Department for Education and the schools would not provide the individual data on pupils’ 11+ entry test scores, and the scores obtained could not be uniquely matched to Key Stage 4 outcomes. While the model presented suggests that there is an advantage to grammar school attendance, the incomplete data means that the study is more a feasibility trial of this strong design than any kind of definitive test intended to settle the debate on grammar school effectiveness. Conducting this design with national data on grammar school selection would create the most powerful evidence so far. To promote an effective and equitable education system for generations to come, those advocating the expansion of grammar schools should make the responsible decision to disclose all grammar school selection data for the purposes of research.

Responding to research evidence in Parliament: A case study on selective education policy

“…Despite our campaigning background, we recognise evidence for the potential benefits of selective secondary school selection, for example, slightly improved GCSE results for borderline 11‐plus pass/fail pupils (Coe et al, 2008; Danechi, 2020; Lu, 2020a, 2020b; POST, 2016). It is worth noting that the report by Coe et al (2008) was for the Sutton Trust—one of the DfE’s ‘approved’ sources of evidence—who cast doubt on what has been termed the ‘grammar school’ effect.…”

“…However, the evidence for either neutral or damaging outcomes represents the vast majority of the research literature (Buscha et al, 2021; Gorard & Siddiqui, 2018; Long et al, 2018). These include evidence that the academic segregation of children: maintains existing inequalities, leading to schools that do not represent their local communities and have a negative impact on children's well‐being (Phillippo, 2019); does not increase social mobility in either relative or absolute terms (Buscha et al, 2021); increases the attainment gaps between socio‐economic groups for long‐term disadvantaged children (Gorard et al, 2021); has little impact on academic attainment for most pupils (Lu, 2020a, 2020b); and that selective schools receive a disproportionately large income (Rowe & Perry, 2021). Thus, the conclusion to be inferred from research evidence is that academic selection has at best a null effect, although it is most likely negative and damaging, and cannot be supported by evidence‐based policy.…”

Does grammar school attendance increase the likelihood of attending a prestigious UK university?

“…These null overall effects of selective systems generally, and grammar schools specifically, were also shown to hold for FSM and non‐FSM pupils alike. That said, studies employing regression discontinuity designs suggest that grammar school attendance may improve GCSE performance by around half a grade per subject for those whose prior attainment was at the lower end of the distribution for grammar school pupils (Lu, 2020; Schagen & Schagen, 2003).…”

Review of Education Early Career Researchers Award 2021

“…The strength and novelty of this study has been recognised through publications in prestigious academic journals, such as the British Educational Research Journal (Lu, 2019), Educational Review (Lu, 2018), and the Cambridge Journal of Education (Lu, 2021). The research findings have been covered widely by the media, including The Times , Independent , Daily Mail , TES , and Forbes .…”