Bryan Caplan seems to think that one should use what one has learned, or, that one should only learn what one will use. But how can you know what learning would be usable in the future? Of course much of what we learn, mathematics for instance, is utterly useless unless you are in science and related fields, but only by learning math could you see how it could be useful and this might well determine your future. Utilitarianism is flawed because it always presumes we know the future. Heck! We don't even know the past or the present, much less the future.
In Response to: Feb. 6, 2017: Caplan *97 Discusses Education’s Real Value; Schultz ’54 Backs New PBS Documentary; and More