1. Au, W. T., Law, Y. K., & Lee, Y. H. (2009, August). Effect of information display on cooperation in a public goods dilemma under a selective-play protocol. Paper presented at The 13th International Conference on Social Dilemmas, Kyoto, Japan.

2. Selective Play An option for leaving the relationship and choosing a new partner (Hayashi & Yamagishi, 1998; Orbell & Dawes, 1991; Tesfatsion, 1995) – “Choice to exit” A trinary-choice game in a PDG (Orbell, Schwartz-Shea, & Simmons, 1984; Hauk, 2003) – “Fully-fledged selective play” (Yamagishi, Hayashi, & Jin, 1994; Yamagishi and Hayashi, 1996) Switch among groups (Ehrhart & Keser, 1999) Bid for partners (Coricelli, Fehr, & Fellner, 2004) Rank partners (Page, Putterman, & Unel, 2002) Hypothesis: Freedom to choose partners enhances cooperation Yamagishi & Hayashi (1996)

3. Display of Endowment Information – Endowment heterogeneity increases cooperation (e.g., Chan, Mestelman, Moir, & Muller, 1996; Bergstrom, Blume, &Varian,1986) – … decreases (e.g., Cherry, Kroll, & Shogren, 2005; Ledyard, 1995) – … does not change (e.g., Warr, 1983; ) Rich contributes more… – More efficacious, critical or efficient (e.g., Van Dijk & Wilke, 1994; Rapoport, 1988; Diekmann, Przepiorka, & Wehrli, 2009) – Altruistic (Becker, 1974) – Inequality aversion (Bolton & Ockenfels, 2000; Fehr & Schmidt, 1999) … less … – Fair share (e.g., Buckley & Cronson, 2006; Kroll, Cherry & Shogren, 2007) – Anticipatory reciprocity (e.g., Cherry, Kroll & Shogren, 2005) – Group identification [reduced when inequality justified] (Smith, Jackson, & Sparks, 2003) Hypothesis: Display of endowment information affects cooperation

4. Display of Cooperation Information Visual anonymity – Anonymity of a person Identifiability (Kerr, 1999; Cress & Kimmerle, 2008) – Anonymity of a person’s behavior or decision Hypothesis: Display of [individualized] cooperation information enhances cooperation (e.g., Sell & Wilson, 1991; Cress & Kimmerle, 2008; Vuolevi & Van Lange, 2009; Weisel & Bornstein, 2009)

5. Experiment Task – Students allocating time between group project [cooperation] vs. individual examination [defection] Voluntary contribution mechanism Linear payoff Endowment size Randomized across trials – 6 hours per week –9–9 – 12 Display of cooperation information – Yes – No Display of endowment information – Yes – No [cooperation] [defection]

6. D D D: 9 hrs. D: (38%) D: 9 hrs. (38%) No infoEndowment infoCooperation infoFull info 120 seconds to select members

7. Experiment Task – Students allocating time between group project [cooperation] vs. individual examination [defection] Voluntary contribution mechanism Linear payoff Endowment size Randomized across trials – 6 hours per week – 9 – 12 Display of cooperation information – Yes – No Display of endowment information – Yes – No Protocols of play – Self-selected – Forced-play Self-selected play – 303 participants – 13-24 participants in an one-hour session – 10 games – HK$50 ( ￥ 620) show-up fee + – Bonus HK$40 - $102 (average $73) ￥ 500 - ￥ 1500 (average ￥ 900) Two randomly selected participants Forced-play – 303 participants – Yoked to the same groupings of self-selected play

8. Select group members Make contribution decision Receive feedback 10 trials

14. Estimation of others’ total contribution Your contribution

15. Estimation of others’ total contribution Your contribution

16. Estimation of others’ total contribution Your contribution

17. Group Project Hours Individual Exam Hours Total Hours Group Project Score Individual Exam Scores Total Scores Total Payoffs Results of Trial 2

18. Endowment Size Rich contributed absolutely more but proportionally the same as poor (similar to Wit, Wilke, & Oppewal, 1992; Van Dijk & Wilke, 1995)

19. Coop Info x Endow Info Display Coop info enhanced cooperation

20. Coop Info x Endow Info Display Hiding endow info enhanced cooperation

21. Coop Info x Endow Info Display Effect of coop info most prominent in the absence of endow info

22. Endowment x Coop Info x Endow Info When cooperation information was present, absence of endowment information affected low and medium endowment players the most

23. Endowment x Coop Info x Protocol Low and medium endowment players most affected by possibility to choose partners when cooperation information was displayed

24. When heterogeneity exists Allow selection of players Hide endowment info and Display cooperation info – Most effective for less rich people