Summary Of 'Play Or Keep'

The experiment “Play or Keep” conducted in class consisted of ten rounds. The professor gave four playing cards to each student, two of which were black and the other two were red. At the beginning of each round, every student had to decide on which two cards to put upside down on the top of the stack of cards from the rest of the class. After all students made a decision, the professor collected the two cards from each student. The student’s earnings depend only on the red cards, as the black cards do not provide earnings. For the first five rounds, the student earned $4 for each red card that he/she decided to keep, while the red cards that were added to the stack affected everyone’s earnings, as the total number of red cards equaled the total number of dollars earned by each student in class. For the last five rounds there was a change as the student earned $2 instead of $4 for each red
After the professor collected the cards from the students, he counted the total number of the red cards in the stack without revealing anyone’s identity on the decision and wrote this number on the whiteboard. Based on that, students were able to calculate their earnings after each round and write them down on their worksheets, along with their decisions and cumulative earnings.
The “Volunteer’s Dilemma” experiment consisted of 10 rounds. Each of us was given two playing cards, one red and one black card. At the start of each round each would play one of the cards by holding it against their chest. After the decisions had been made, but without making it known to the others the professor would pair us randomly with somebody in the class. The earnings in dollars were determined by the color of the cars played. The red card meant that the students was volunteering. The payoffs are: if there is no volunteer: $0.00 if there is at least one volunteer and you DO NOT volunteer: