Before the main part, the usbjects complete a stage eliciting their social preferences. Then, the main part starts. The subjects participate in a computerized repeated real-effort experiment with a mundain typing task. There are one unincentivized trial round and five incentivized rounds. Their performance is measured by the number of finished tasks in a 4-minute-long round. For this, they receive a flat rate payment of 0.20 SGD per task. That is, their gross payment in a round is equal to 0.20 SGD x tasks. From Round 2, they are subjected to a tax rate of X percent. The subtracted amount is redistributed evenly within their randomly matched fixed groups of 3 participants. The session concludes with a demographic questionnaire. The treatments differ in the tax rate X: (10, 50 or 70%) and the provision of feedback between rounds (feedback vs no feedback).