ABSTRACT
This study aims to identify which socio-economic status (SES) variables have the best predictive validity for academic achievement, based on the international data sets of the Programme for International Student Assessment (PISA) in 2012, 2009, 2006, and 2003. From among 10 SES measures, two composite variables - Index of economic, social and cultural status (ESCS) and Home possessions (HOMEPOS) - showed superior predictive power for student achievement. Their pan-cultural correlations with the PISA 2012 mathematics achievement were r = .40 and r = .36, respectively. Parental occupation status (r = .33) outperformed all other single measures of SES, including parental education (r = .29). Only two SES variables (i.e., family wealth and home possessions) showed non-linear relationships with academic achievement. We conclude with practical implications and recommendations for using SES measures as predictors of student achievement in educational research and point to the importance of a theoretical alignment between SES measures and particular issues to be addressed.