R Code for Mathematics Achievement Growth, Mobility, and Socioeconomic Gradients: Evidence from the TIMSS 2023 Longitudinal Study [Dataset]

[ENG]This code contains the complete R analysis code used to produce all results, tables, and figures reported in the associated publication. The code implements sample construction, achievement growth and mobility analysis, Matthew-effect regression models with CR2 cluster-robust standard errors, and quasi-binomial logistic regression for SES gradients in upward mobility. Analyses use publicly available data from the TIMSS 2023 Longitudinal International Database (Grade 4–5 component, nine education systems).