Association for Public Policy Analysis & Management

Recent evidence from the US shows that the gap in academic achievement between students from high-income and low-income families has grown substantially over the past 40 years (Reardon 2011). This study examines whether these increasing socioeconomic achievement gaps are part of a worldwide trend. It is the first to compare SES achievement gaps over the entire history of large-scale cross-national assessments, dating back to the First International Mathematics Study (FIMS) in 1964. The study combines 27 datasets across 106 countries and 48 years and represents about 4.8 million students. Three measures of family socioeconomic status are available in most of the datasets: parents’ education, parents’ occupation, and the number of books in the home. Results indicate that on average worldwide, SES achievement gaps have increased dramatically for all three measures of SES. Among OECD countries, achievement gaps based on parents’ education have increased by about 20%, gaps based on parents’ occupation have increased by about 35%, and gaps based on books in the home have increased by about 80%. In less developed countries, the increases are even greater. In most countries, gaps have increased primarily between the middle and the bottom of the SES distribution, raising concerns about equality of opportunity for the most disadvantaged students.