Posted by Jan-Eric Nilsson on September 24, 1997 at 08:37:39:
During experiment 3 (taxes) this person who is present in every group was late; she did, more precisely, turn up in the middle of Session 1. Nice guys as we are, we invited here to join in for sessions 2 and 3. We also gave the group theoretical data pertaining to the larger number of producers. And of course they came to the conclusion that a tax on producers will increase total producer surplus!
I could tell them afterwards why they got things wrong. Moreover, it was possible to use this mistake to illustrate the meaning of Ceteris Paribus; this was of course a situation where two things happended simultaneously, i.e. both a tax on producers and a larger number of producers as compared to the no-tax case.
The point which I want to share with you is that perhaps this has made my students more aware of the deep significance of Ceteris Paribus than what typically is the case.
Jan-Eric