The authors of this article implement a quasi-experimental strategy to estimate peer effects in economic education by exploiting the institutional setting in a large public university in China, where roommates are randomly assigned conditional on a student's major and province of origin. They found significant impacts of peer academic quality, measured as roommates' average scores on the national College Entrance Exam, on first-year economics students' scores in first-year microeconomics, macroeconomics, and accounting courses. They also found nonlinearity in peer effects: Roommates' academic ability has significant effects for academically weak students but not for academically strong students.