@EdWorkingPaper{ai26-1569,
title = "Unpacking the Socioeconomic Status Gap in Exam-Based School Admissions",
author = "Andrew Dustan, Diana Ngo",
number = "1569",
year = "2026",
month = "September",
URL = "http://www.edworkingpapers.com/ai26-1569",
abstract = {We analyze the large socioeconomic status (SES) gaps in public high school assignments in Mexico City, a centralized choice system with exam-based admissions. Using a rich structural model, decomposition, and simulations, we find that placement score differences explain 83% of the gap in assignment to elite schools, contrasted with preferences (6%) and location (5%). For less-preferred technical schools, preferences explain 64% of the gap, while score differences account for 34%. High-SES students have a substantial advantage on the placement test beyond what is predicted by multiple contemporaneous ability measures, raising concerns about the distributional impacts of exam-based admissions.},
}