The Effect of Communication Media on Cooperation

Abstract. We examine how communication affects cooperation with the help of seven standard public goods experiments that only differ with respect to the medium of pre‐play communication. Our treatments include bidirectional and unidirectional communication via (mostly electronic) auditory and/or visual channels. The results suggest that successful cooperation is attributable to the opportunity of ‘coordinating’ behavior in the communication phase. Furthermore, both the level and the stability of cooperation significantly interact with the communication medium, even though the content of communication is remarkably similar across the communication treatments.     

Fairness in the Mail and Opportunism in the Internet: A Newspaper Experiment on Ultimatum Bargaining

Abstract. On 11 May 2001, readers of the Berliner Zeitung were invited to participate in an ultimatum bargaining experiment played in the strategy vector mode: each participant chooses not only how much (s)he demands of the DM1,000 pie but also which of the nine possible offers of DM100, 200, …, 900 (s)he would accept or reject. In addition, participants were asked to predict the most frequent type of behavior. Three randomly selected proposer–responder pairs were rewarded according to the rules of ultimatum bargaining and three randomly chosen participants of those who predicted the most frequent type of behavior received a prize of DM500. Decisions could be submitted by mail, fax or via the internet. Behavior is described, statistically analyzed and compared to the usual laboratory ultimatum bargaining results.     

MODELING ON THE BASIS OF MODELS

A large part of official economic data sets is produced with the help of assumed functional relations between variables. Constructing economic models on the basis of such model-generated data results in a "modeling on the basis of the results of modeling." This common procedure can lead to consequences that seriously endanger the quality of empirical analyses. After discussing some of these dangerous consequences the authors explore the reasons behind this development. To avoid some of the most severe difficulties a "Charter for Compilation and Correct Handling of Economic Data" is proposed.