In each round, each group member receives the same amount of money, and each simultaneously chooses how much of it to contribute to a water purification project.
Use the slider to choose your amount and press Contribute.
Payoff Computation
Your payoff depends both on your contribution and the contributions of the other members of your group.
Each citizen benefits from the total amount contributed by the all members of the group
Each round, your payoff equals the amount you did not contribute (your endowment - your contribution) plus each player's benefit (total group contributions * the Rate of Return)
Example
You start with $20; Rate of Return is 50%
You contributed $12; total group contributions were $20
Total Payoff
=
( Endowment
–
Your Contribution )
+
( Rate of Return
×
Total Contributions )
$18
=
( $20
–
$12 )
+
( 50%
×
$20 )
You contributed $12; total group contributions were $30