Peter Kollock's research while affiliated with Georgia Institute of Technology and other places

One of the most robust findings in the sociological literature is the positive effect of communication on cooperation and trust. When individuals are able to communicate, cooperation increases significantly. How does the choice of communication modality influence this effect? We adapt the social dilemma research paradigm to quantitatively analyze different modes of communication. Using this method, we compare four forms of communication: no communication, text-chat, text-tospeech, and voice. We found statistically significant differences between different forms of communication, with the voice condition resulting in the highest levels of cooperation. Our results highlight the importance of striving towards the use of more immediate forms of communication in online environments, especially where trust and cooperation are essential. In addition, our research demonstrates the applicability of the social dilemma paradigm in testing the extent to which communication modalities promote the development of trust and cooperation.

The study of social dilemmas is the study of the tension between individual and collective rationality. In a social dilemma, individually reasonable be-havior leads to a situation in which everyone is worse off. The first part of this review is a discussion of categories of social dilemmas and how they are modeled. The key two-person social dilemmas (Prisoner's Dilemma, Assur-ance, Chicken) and multiple-person social dilemmas (public goods dilem-mas and commons dilemmas) are examined. The second part is an extended treatment of possible solutions for social dilemmas. These solutions are or-ganized into three broad categories based on whether the solutions assume egoistic actors and whether the structure of the situation can be changed: Mo-tivational solutions assume actors are not completely egoistic and so give some weight to the outcomes of their partners. Strategic solutions assume egoistic actors, and neither of these categories of solutions involve changing the fundamental structure of the situation. Solutions that do involve chang-ing the rules of the game are considered in the section on structural solutions. I conclude the review with a discussion of current research and directions for future work.

An experiment is used to investigate the effects of uncertainty on patterns of exchange. The role of reputation as an important factor related to the formation of stable exchange relations is examined. In addition, some of the consequences of different patterns of exchange-in particular, how different exchange conditions lead to different levels of trust among trading partners-are investigated. The results of the experiment indicate significant differences in the level of commitment, concern for one's own and others' reputation, and the level of trust that emerge when uncertainty (in the form of information asymmetries) is varied.

Using computer simulations that permit degrees of cooperation and introduce "noise" into the environment, I explore the benefits of strategies in which actors use different accounting systems to track ongoing exchanges. By relaxing some stringent assumptions of past work, I chart the conditions under which cooperation may emerge when actors can show degrees of cooperation and when actors' moves are misperceived. Results provide evidence that strategies employing a relaxed accounting system have many advantages.

The purpose of this study is to investigate how cooperation might emerge given the following circumstances: the presence of social dilemmas (in which individually rational behavior leads to collectively irrational outcomes), the absence of perfect information, and the possibility of degrees of cooperation. This investigation includes an analysis of accounting systems in exchange relations and argues for the benefits of a relaxed accounting system under the conditions enumerated above. The problem is examined in an experimental study in which subjects interacted with a variety of simulated actors. The highest levels of cooperation and the greatest earnings resulted when subjects interacted with simulated actors using a strategy that involved some form of relaxed accounting system. In addition, simulated actors using a relaxed accounting system did as well or better for themselves than simulated actors using more restrictive strategies.