The experiment consists of 30 rounds. All participants keep the role and the number assigned
to them throughout the experiment. After each round you will be informed about what has
happened and you will be reminded of your earnings and your total earnings so far.
Moreover, A-participants can keep track of some of the history of B-participants. There will
be a screen depicting the history of B-participants. For each round and each B there will be a
coloured little #. A black # indicates that in this particular round the B-participant had nothing
to decide because the A he had been matched with picked option X. A red # indicates that B
picked “left”. A green # indicates that B picked “right”. Finally, a grey # simply indicates that
no information is available.
In each round each A-participant obviously learns what the B-participant did that he had been
matched with. And this will be reflected by a coloured little # in the above mentioned screen.
Moreover, each A will be informed about one additional B in each round. In particular, A1
will also be informed about the B-participant that A2 had been matched with, A2 about the B-
participant that A3 had been matched with, A3 about the B-participant that A4 had been
matched with, and A4 about the B-participant that A1 had been matched with.
Accordingly, for each round A’s will see for two B’s either a black, green, or red # and for
two others grey #’s. Or to put it differently, each round the behaviour of each B will not only
be observed by the A he had been matched with but also by one other A.
These are the rules. You can trust us that everything will happen exactly according to these
rules. Take your time going over these instructions again. And feel free to ask questions. But
don’t shout! Simply raise your hand.
Your total earnings that equal the sum of your individual earnings in the 30 rounds (plus your
show-up fee of £5) will be paid to you right after the experiment in cash.
You have role A.