Opportunity cost

I then wrote to a number of well-known philosophers, asking each of them if they would supervise a course-by-mail, consisting of my writing letters to them about their work, getting responses from them, and ultimately providing comments on a paper I wrote. Nancy Cartwright, Lynne Rudder Baker and Nathan Oaklander agreed to do this for me. They were all extremely generous with their time, and I owe all three of them, along with Quentin, an enormous debt.

That is from LA Paul, who has since become a very accomplished philosopher.  How many economists would help out in the same way?  Hat tip goes to Kieran Healy.