Experimental research on first price sealed bid auctions has usually involved repeated settings with information feedback on winning bids and payoffs after each auction round. Relative to the risk neutral Nash equilibrium, significantly higher bidding has been reported. The present paper reports the results of experimental first price auctions with n = 7 where feedback on payoffs and winning bids is withheld. Under these conditions, average bidding is below the risk neutral Nash equilibrium prediction but converges to it with repetition.

Recent theoretical research on oligopolistic competition suggests that under certain conditions prices increase with the number of competing firms. However, this counterintuitive result is based on comparative-static analyses which neglect the importance of dynamic strategies in naturally-occurring markets. When firms compete repeatedly, supra-competitive prices can become sustainable but this is arguably more difficult when more firms operate in the market. This paper reports the results of laboratory experiments investigating pricing behavior in a setting in which (static) theory predicts the counterintuitive number effect. Under a random matching protocol, which retains much of the one-shot nature of the model, the data corroborates the game-theoretic prediction. Under fixed matching duopolists post substantially higher prices, whereas prices in quadropolies remain very similar. As a result, the predicted effect is no longer observed, and towards the end the reverse effect is observed.

Laboratory experiments are an important methodology in economics, especially in the field of behavioral economics. However, it is still debated to what extent results from laboratory experiments are informative about behavior in field settings. One highly important question about the external validity of experiments is whether the same individuals act in experiments as they would in the field. This paper presents evidence on how individuals behave in donation experiments and how the same individuals behave in a naturally occurring decision situation on charitable giving. While we find evidence that pro-social behavior is more accentuated in the lab, the data show that pro-social behavior in experiments is correlated with behavior in the field.

We conduct a representative dictator game in which students and random members of the community choose both what charity to support and how much to donate to the charity. We find systematic differences between the choices of students and community members. Community members are much more likely to write in their own charity, community members donate significantly more ($17), on average, and community members are much more likely (32%) to donate the entire $100 endowment. Based on this evidence, it does not appear that student behavior is very representative in the context of the charitable donations and the dictator game.

This paper theoretically and experimentally explores a fixed price mechanism in which, if aggregate demand exceeds supply, bidders are proportionally rationed. If demand is uncertain, in equilibrium bidders overstate their true demand in order to alleviate the effects of being rationed. This effect is the more intense the lower the price, and bids reach their upper limit for sufficiently low prices. In the experiment we observe a significant proportion of equilibrium play. However, subjects tend to overbid the equilibrium strategy when prices are high and underbid when prices are low. We explain the experimental evidence by a simple model in which the probability of a deviation is decreasing in the expected loss associated with it.

We investigated the importance of the social context for people's voluntary contributions to a national park in Costa Rica, using a natural field experiment. Some subjects make actual contributions while others state their hypothetical contribution. Both the degree of anonymity and information provided about the contributions of others influence subject contributions in the hypothesized direction. We found a substantial hypothetical bias with regard to the amount contributed. However, the influence of the social contexts is about the same when the subjects make actual monetary contributions as when they state their hypothetical contributions. Our results have important implications for validity testing of stated preference methods: a comparison between hypothetical and actual behavior should be done for a given social context.