Our compulsory public school system is supposed to be “the great equalizer.” By providing the same schooling to everyone, it is supposed to promote equal opportunities for young people regardless of their socioeconomic background. In fact, however, the system has never been a great equalizer, and research indicates that it is even much less an equalizer today than it was in the past.
A few years ago, Sean Reardon of Stanford University published an analysis of the findings of many studies showing, over all, that the gap in achievement test scores between students from the richest 10% of families and the poorest 10% grew by 40 to 50 percent between the mid 1970s and the early 2000s.. The gap exists at all grade levels, but is much larger in the later years of schooling than in the early years. By the middle of high school, the average test scores for students from the bottom 10% in income are three to six grade levels (depending on the type of test) below those of students from the top 10% in income.