The Opportunity Cost of an Email

There’s a midterm this week in my class of 550 students, and I have been deluged with emailed questions, many procedural, that are covered in the online daily class summary. (For example, is the test being given in class?)  In the old days, when students came to office hours to ask questions, I wouldn’t have gotten most of these queries.  Regrettably, a student’s opportunity cost of emailing is much less than the cost of an office visit.

Why don’t I raise the cost to students by refusing to answer these emails?  If I thought that would deter all such questions and visits, I would refuse. But even if 20 percent of the emails translate into student visits, I’m better off answering the emails, since each takes me at most 1/5 as long as dealing with the question face-to-face in my office.  This is annoying, but I believe I save time this way.