We consider the social choice situation with two players and three alternatives. Players are denoted by 1 and 2. Alternatives are denoted by a,b, and c. There are four different treatments each treatment corresponding to a different mechanism players participate in.Each mechanism depends on the public priority list. For simplicity in illustration all priority lists are assumed to be abc.
T1: Dominant Strategies. Alternative a is made default. Players are asked whether they want to implement b instead of a. If both agree, then b is implemented. Otherwise a is implemented
T2: Range Dominance-1. Alternative a is made default. Players are asked whether they want to implement b or c instead of a. If both choose b, then b is implemented. If both choose c, then c is implemented. Otherwise a is implemented.
T3: Range Dominance-2. Players are asked whether they want to veto a,b, or c. Alternative is vetoed if at least one person vetoed the alternative. If a is not vetoed, then a is implemented. If a is vetoed and b is not, then b is implemented. Otherwise c is implemented. To ensure better design parallelism we implement this treatment through the subjects casting two votes for the alternatives they support. The alternative they do not vote for is the one we consider vetoed.
T4: Strategically Simple. Alternative a is made current default. Players are asked whether they want to replace the current default with b. If they both agree, then b becomes current default. Otherwise, a stays current default. In the next stage, players are asked whether they want if they want to replace the current default with c. If both agree, then c is made current default. Otherwise current default stays the same. Finally, the current default is implemented.
Out of six preference profiles we consider case with 4 preference profiles for the sake of maximizing the size of the effect. In particular, we remove the two preference profiles that rank the default alternative as top. That is, for the priority list abc we remove abc and acb profiles. Thus, the players can have preferences: bac, bca, cab, or cba.
Subject repeatedly play 20 periods of the experiment with random rematching after every period. The payment is determined by randomly picking one round once experiment is completed. Alternatives are color-coded: blue, green and orange. Mapping between underlying alternatives and labeling is randomized. The priority list is randomized at the period level. The type subject have is randomized every period.
Subjects participate in two post experimental tasks. First is the standard beauty contest game. Second is a risk elicitation task.
In beauty contest task subjects are asked to guess the 2/3 of the average guess of other subjects in the session. Player who has guessed closest to the target is a winner and receives the compensation. This is a standard beauty contest task used to reveal cognitive sophistication of subjects.
In the risk-elicitation task subject is asked a single question. Whether they prefer the payment corresponding to the second-best alternative for sure versus the lottery of the equally likely payments corresponding to the first- and third-best alternatives. This test is necessary as some of the forecast might be sensitive to successfully inducing not only ordinal but also cardinal preferences.