Of all college admission criteria, scores on nationally normed tests like the SAT and ACT are most affected by the socioeconomic background of the student. The effect of socioeconomic background on test scores has grown substantially at University of California over the past two decades, and tests have become more of a barrier to admission of disadvantaged students. In 1994, socioeconomic background factors—family income, parents’ education, and race/ethnicity—accounted for 25 percent of the variation in test scores among California high school graduates who applied to UC. By 2011, they...