Substituting Physical and Human Capital

A student befriends me on facebook, leaving this message:

Your econ textbook helped us out tremendously this year.....especially because our teacher has no clue what she's doing, and so we have to read the text to understand what's happening.

This reminded me of a professor I know who once told me that he liked to assign the most confusing textbook he could find. By comparison, his lectures would seem like paragons of clarity.

He was joking (I think).