As an economist and an avid reader I certainly appreciated Marketplace Money’s description of the concept of opportunity cost:
“The late Robert Eisner, an economist at Northwestern University, somewhat tongue-in-cheek illustrated opportunity cost this way. The cost of buying and reading his book–The Misunderstood Economy–was not only the dollars spent on it, but also the value of the time spent reading it and the alternative use of that time. In other words, his book should only be read if you believe your return, both in enlightenment and enjoyment exceeds its opportunity cost, that is, money spent on the book and the time required to read it.“