I get invitations to guest lecture at English universities on Wednesdays, but almost never for Wednesdays in the U.S. I didn’t know why this difference exists, until one of the inviters mentioned that many English universities keep Wednesday afternoons free of regularly scheduled classes, historically so students can engage in inter-scholastic athletics. Universities thus have created a positive coordination externality.
We economics professors don’t engage in these athletic endeavors, but the athletic coordination creates a positive externality for economists: In scheduling seminars, we know that most faculty members at other universities are free to visit, and most of our colleagues should be available to attend the seminar. (HT: NT)