The job of textbooks is to separate brilliance, which has zero marginal cost, from individual attention, which is labor-intensive. Everybody is better off when the few brilliant teachers write books that the many dedicated ones can teach from.

MOOC’s do the same job better. They are cheaper to make and distribute. They are cheaper to improve on, because student response is automatic and quite precise: all you have to do is look for videos most rewound, or quiz answers most missed. Improvements can be spliced in as needed, one four-minute video replacing another. MOOC’s are also much better at avoiding bloat. Textbooks grow thicker and more colorful over time, driven by relentless yearly print runs. It is not clear how much of this reflects truly new content, more effective delivery, or the need to kill off the resale market. With MOOC’s, there is no such uncertainty. The resale market is not a concern. Courses that are not watched will be abandoned. Lectures rewound a lot or whose accompanying quizzes have low pass rates will be re-shot, improved. And videos preserve the kind of author’s flair for delivery that is lost on the printed page no matter how colorful the latest version is, or how interactive the accompanying website.

Many trees are felled for making textbooks that are returned to the publisher. While they are out, they are clutter that makes it hard to find the good ones: they’re all equally thick and colorful and pushed by equally enthusiastic reps. MOOC’s, on the other hand, produce all kinds of vital statistics – viewership, attrition rate, forum participation, topics most discussed, etc. – as soon as they go live. They are easy to kill off if they don’t catch on and it does not take long to know whether they might. MOOC’s may look like a monoculture, but what looks like diversity in textbooks is just market inefficiency.

MOOC’s don’t work that well on their own for the same reason that textbooks don’t: both are complements to individual attention, not substitutes for it. But MOOC’s paired with a flipped classroom will do a better job than textbooks paired with a reading schedule have done so far. Thanks to them the workers of the future will be more productive than we are.