Intervention (Hidden)
Section 1
- In Section 1 of the experiment, subjects will play the Stag Hunt game 7 times with random matching at the beginning of each period, and without feedback. The basin of attraction of Stag will vary across the 7 periods.
- We will we use the choices in Section 1 to compute each subject’s Coordination Attraction Score (CAS), which measures the frequency with which that subject chooses Stag, weighting each choice of Stag by the size of the basin of attraction of Stag in that period, and normalizing by the sum of the basin sizes so that CAS lies between zero and one.
Section 2
- In Section 2 of the experiment, subjects will play 9 matches with random rematching at the beginning of each match. The first match will be an unincentivized training match.
- In each match, two subjects will play a two-part stage game for 3 rounds. In part 1 of each round, the subjects will simultaneously choose whether or not to invest in team skill, where investment incurs a sunk cost c =15. Whenever a subject invests, team skill T will increase by b > 0 for the duration of the match (that is, for the current round and any future rounds of the match). In part 2 of each round, after observing the investment decisions in part 1, the subjects will simultaneously choose the team task or the individual task. If both subjects choose the team task, they will each receive a payoff given by the current level of team skill T, where the initial T=87. When a subject chooses the individual task, she receives 73 for sure. When a subject chooses the team task alone she receives 17.
- At the beginnning of each match, b will be drawn uniformly from { 2, 4, ..., 20 } , and will stay the same for the duration of the match.
- Alongside subgame-perfect Nash equilibrium, we also use the basin of attraction of investment to help develop our hypotheses about behavior in Section 2. To calculate the basin of attraction of investment, we suppose that with k rounds remaining (including the current round), a player believes with probability β_k that the other player will always choose the team task, and believes with probability 1 − β_k that the other player will always choose the individual task. The basin of attraction of investment is then the set of beliefs that makes investment optimal, taking into account the dynamic benefit of investment in the current and any future rounds. Investment is optimal iff (β_k)bk ≥ c. Thus, the size of the basin of investment is max{0,1−c/(bk)}.
Section 3
- In Section 3 of the experiment, subjects will complete a test of cognitive ability followed by a test of theory of mind. Each test will last 10 minutes. We will pay subjects $2 for completing each test.
- To measure cognitive ability, we will use the 11-item test of matrix reasoning from the International Cognitive Ability Resource. Each item has a single correct answer, and the score on the test counts the number of correct answers.
- To measure theory of mind ability, we will use the 36-item Reading the Mind in the Eyes Test (RMET). Each item has a single correct answer, and the score on the test counts the number of correct answers.
- We also measure two demographics, age and gender, but we do not hypothesize any specific relationship between these demographics and behavior in the experiment.
Instead, these demographics will serve as controls where appropriate.
Exchange rate
- We will convert experimental points at the rate of 125 points = $1. Subjects will further earn a show-up fee of $5.
Hypotheses
- Hypothesis A. Across matches, investment in team skill increases in b.
- Hypothesis B. Investment in team skill falls as the rounds progress within a match. The decline from the second to the third round is larger than the decline from the first to the second round.
- Hypothesis C. Investment in team skill increases with a subject’s CAS, cognitive ability, and theory of mind ability.