Thinking Alike

A conversation I had with a student last week went something like this:

Student: Professor Mankiw, if you could recommend just one book, what book would it be?

Me: Am I allowed to recommend my favorite textbook?

Student: No. Textbooks are disallowed.

Me: In that case, I'll suggest Milton Friedman's Capitalism and Freedom.

Student: That's funny. That's the same answer I got when I asked this question of Professor Summers.