The free Web tutoring service “Khan Academy” has gotten much well-deserved attention, including a feature story in the current issue of Wired. That story includes a quote that literally took my breath away:

Even if Khan is truly liberating students to advance at their own pace, it’s not clear that the schools will be able to cope. The very concept of grade levels implies groups of students moving along together at an even pace. So what happens when, using Khan Academy, you wind up with a kid in fifth grade who has mastered high school trigonometry and physics—but is still functioning like a regular 10-year-old when it comes to writing, history, and social studies? Khan’s programmer, Ben Kamens, has heard from teachers who’ve seen Khan Academy presentations and loved the idea but wondered whether they could modify it “to stop students from becoming this advanced.”

This attitude is a natural outgrowth of our decision to operate education as a monopoly. In a competitive marketplace, educators have incentives to serve each individual child to the best of their ability, because each child can easily be enrolled elsewhere if they fail to do so. That is why the for-profit Asian tutoring industry groups students by performance, not by age. There are “grades,” but they do not depend on when a student was born, only on what she knows and is able to do.

But why should a monopolist bother doing that? It’s easier just to feed children through the system on a uniform conveyor belt based on when they were born.