Abstract:Considerable experimental evidence has been collected on rules enhancing contributions in public goods dilemmas. These studies either confront subjects with pre-specified rules or have subjects choose between different rule environments. In this paper, we completely endogenize the institution design process by asking subjects to design and repeatedly improve rule sets for a public goods problem in order to investigate which rules social planners facing a social dilemma "invent" and how these rules develop over time. We make several noteworthy observations, in particular the strong and successful use of framing, the concealment of individual contribution information and the decreasing use of punishment. We are deeply indebted to Reinhard Selten for proposing this research and for our intensive discussions throughout the project. Special thanks go to our seminar participants for their enthusiasm while taking part in this study. We also thank participants at seminars in Bonn and Erfurt for their inspiring comments, as well as our colleagues at the chair of microeconomics for their tireless help in testing the experimental software programs, as well as for the fruitful discussions along the way.2

In this paper, we experimentally approach the question of which aspects of a voting procedure are able to restrict elected candidates' willingness to use their power in an opportunistic way. For this purpose, we rule out re-election concerns and analyze whether the presence of a vote by itself matters for the exercise of power. We compare two kinds of electoral campaigns: self-descriptions of personality and promises regarding prospective in-office behavior. We find that social approval as conveyed by a vote does not suffice to induce pro-social choices by elected candidates. On the other hand, when campaigns are promisebased, elected candidates transfer more to their recipients than candidates selected by a random draw even though promises do not differ. This refutes explanations based on a taste for consistency or costs of lying. In contrast, the fact Hong Geng, Laboratory for Experimental Economics, University of Bonn, Germany (honggeng@gmx.de). Arne Robert Weiss, University of Cologne & Center for Empirical Research in Economics and Behavioral Sciences, University of Erfurt, Germany (arne.weiss@wiso.uni-koeln.de). Irenaeus Wolff, University of Konstanz, Germany / Thurgauer Wirtschaftsinstitut (TWI), Kreuzlingen, Switzerland (wolff@twi-kreuzlingen.ch).We thank Gari Walkowitz as well as Stephan Tontrup for their support in designing the experiment and Mareike Hoffmann as well as Fu Hao for running the German sessions and the follow-up sessions in China, respectively. We are indebted to Jia Jiamin and the industrious staff at the Herbert A. Simon, and Reinhard Selten Behavioral Decision Research Lab for their support as well as to CEREB and the Bonn Laboratory for Experimental Economics for funding the experiment. Our thanks further go to Katharine Bendrick, Mareike Hoffmann, Bettina Rockenbach,Özgür Gürerk, members of CEREB, and to the associate editor and two anonymous referees, for valuable comments on earlier versions of the paper. 695Konstanzer Online-Publikations-System (KOPS) URL: http://nbn-resolving. de/urn:nbn:de:bsz:352-0-320272 Erschienen in: Journal of Public Economic Theory ; 13 (2011), 5. -S. 695-719 https://dx.doi.org/10.1111/j.1467-9779.2011 696 that the correlation between dictators' promises and their beliefs on voter expectations is considerably strengthened in the presence of a vote offers support to a guilt-aversion hypothesis. However, this support is qualified by the correlation between dictators' second-order beliefs and their choices, which is weaker than predicted. Overall, our results suggest the power of voting to limit the self-oriented exertion of power is limited and context specific.

Carpenter and Matthews (2009) examine the cooperation norms determining people's punishment behavior in a social-dilemma game. Their ndings are striking: absolute norms outperform the relative norms commonly regarded as the determinants of punishment. Using multiple punishment stages and self-contained episodes of interaction, we disentangle the eects of retaliation and norm-related punishment. An additional treatment provides data on the norms bystanders use in judging punishment actions. Our results partly conrm the ndings of Carpenter and Matthews: only for the punishment-related decisions in the rst iteration is the absolute norm outperformed by the self-referential norm set by the punisher's own contribution. For the decisions in all later iterations, as well as for bystanders' support in all iterations, the absolute norm organizes our data best. In contrast to the study by Carpenter and Matthews, we nd an absolute norm of 3/4 of players' endowments to be both consistent across decisions and relatively stable over time.

h i g h l i g h t s • I determine the Nash-equilibria resulting from participants' elicited preferences. • Multiple equilibria are relatively frequent even in a standard 3-player setting. • Multiple equilibria are more frequent than Fehr & Schmidt's (1999) model predicts. • Hence, omnilateral defection at the end of repeated public-good games is surprising.