Students enter school with different levels of academic readiness, and these differences increase through the grades. Mr. Grubb uses lessons gleaned from Finland's schools to suggest ways in which the U.S. could decrease this inequality. EVERY LEVEL of education in our country suffers from one particular form of inequality. Whether in kindergarten or in college, some students enter ready to perform at higher levels than others--because of various dimensions of family background, or the quality of prior schooling, or motivation, or discouragement caused by years of disparaging treatment, or physical or mental health conditions, or too many other factors to catalogue easily. Then the question is whether schools and colleges recognize these differences and work effectively to reduce them, or whether they ignore inequalities and leave them to students themselves and parents and successive levels of schooling to correct--or fail to correct. The problem I call dynamic inequality arises from the fact that students start formal schooling at age 5 or 6, and the initial differences among them continue to grow over time. For example, modest black/white differences at the beginning of kindergarten, largely explained by simple socioeconomic variables, increase until the spring of third grade; another estimate is that initial black/white differences are roughly doubled by the end of 12th grade, though with changes in the metric by which differences are measured, the gap may grow as much as fourfold. (1) Similarly, the range of scores for the middle 50% of students on the Peabody Individual Achievement Test widens steadily and monotonically over time. (2) In my analysis of NELS:88 data over eighth, 10th, and 12th grades, test scores diverge in predictable ways: over these five years, the gaps become larger among racial/ethnic groups, among groups defined by family background (especially maternal education and parental aspirations for their children), and between genders, with male dominance in math, history, and science scores and female dominance in English scores growing over time.(3) There's no reason to think that the growth in inequality is steady. At certain points in our education system, there are likely to be small or explosions of inequality. For example, in the transition from eighth to ninth grade, some students (mostly those performing at low levels) leave school or fail to attend, so their progress grinds to a halt on all measures of outcomes. Some students are assigned to remedial tracks, to general tracks, or to the remnants of traditional vocational education, and their progress is likely to be relatively small. At the other extreme, high-performing students get into honors or AP courses, and under pressure from these advanced curricula their progress is likely to be significantly higher than that of other students. Many students in the middle follow middling courses in high school, neither honors nor remedial, and their progress might be steady but modest. Other bursts of inequality might take place at the transition into middle school, when students begin taking a variety of subjects from different teachers and when tracking often starts. Some educators have mentioned the transition from third to fourth grade as a similar problem, when teachers stop teaching how to read and how to do basic arithmetic; those students who have not mastered these basic skills then fall further and further behind as basic skills are used to explore more complex learning. And the transition into postsecondary education surely leads to another boom in inequality, as some students enter the best universities in the world, dropouts usually fail to gain access to further schooling, and everyone in between strives for access to a system of postsecondary education that is highly differentiated. These patterns of dynamic inequality create enormous differences by grade 12, when some individuals have dropped out and are still reading at the sixth-grade level, while others have accumulated many AP credits and are about to enter top-ranked universities. …