This study examines the relationship between mathematics in high school and labor force earnings 10 years later. Using a series of statistical models to net out the true effect of curriculum, the authors control for as many other factors as the data allow: the student's demographic characteristics, measures of student motivation and ability, family background, and high school characteristics. After taking into account all of these factors, the authors find the direct relationship between curriculum and earnings remains quite strong. The analysis also shows that it is not simply the number of math courses a student takes that is important; what matters more is the extent to which students take more-demanding courses.