In the 2012 Programme for International Student Assessment, students from Shanghai, Hong Kong, Macao, and Taipei, where the classroom disciplinary climate of schools was relatively strict, were top performers in mathematics. In this study, two-level linear analyses showed that the classroom disciplinary climate of schools significantly affected student mathematics achievement in the four Chinese economies, indicating that school and economy-level inequality were related to the classroom disciplinary climate of schools. Additionally, residual analyses showed that students in different percentiles within economies, as well as students in the same percentiles of different economies, benefited or hindered differently from classroom disciplinary climate of schools, hinting at shrinking individual-level differences in student mathematics achievement. Most students in Shanghai and Hong Kong benefited from an orderly disciplinary climate in their schools, particularly medium and high performers in Shanghai, while most students in Taipei and Macao suffered from a disruptive disciplinary climate in their schools. Statistically, Taipei would replace Shanghai and top the four Chinese economies in student mathematics performance if all schools in the four had a disciplinary climate similar to the Organisation for Economic Co-operation and Development average.