The acquisition of information is an important feature in most auctions where one’s exact private valuation is unknown ex-ante. We conducted the first experiment in testing a risk-neutral expected surplus maximization model with this feature. Varying the auction format and the cost of information acquisition we found bidders in most cases acquired too much information. Moreover, bidders who remained uninformed placed bids significantly below the optimal bid. The general prediction concerning revenue and efficiency remains valid, as a higher information cost was associated with lower revenues and efficiency rates. We explore different ex-post explanations for the observed behavior and show that regret avoidance can explain the data while risk aversion and ambiguity aversion cannot.

Afriat’s (Int Econ Rev 14(2): 460–472, 1973) critical cost efficiency index is often used to measure the extent to which experimental choice data violate the axioms of revealed preference. Under certain conditions, the index yields a value of one—which typically signifies rational choice—when, in fact, the choice violates the axioms. We term this a cost efficient violation (CEV) of the axioms, clarify the conditions under which it arises, and find that CEVs comprise the majority of violations in three of four studies reviewed. We suggest changes in experiment design to eliminate or reduce the likelihood of CEVs.

I investigate the impact of proportional representation (PR) and majoritarian rule (MR) on voter turnout and minority representation using theory and experiments. Numerous empirical studies have compared turnout across PR and MR. However, the empirical evidence is mixed. I show theoretically and experimentally that the comparison of turnout across PR and MR depends on the size of the minority but the empirical papers on the topic do not control for it. I also show that, in both theory and data, PR improves minority representation at a minute cost to efficiency if the size of the minority is sufficiently large. However, the representation of a small minority does not show a remarkable improvement under PR, unlike what the theory predicts. I conjecture that, under PR, there is a discouragement effect for the small minority because the PR system that I employ has an election threshold. As a result, the impact of the voting system on representation may be sensitive to both the size of the minority and the degree of proportionality.

We combine data from a randomized evaluation and a laboratory experiment to measure the causal impact of human capital on respect for earned property rights, a component of social preferences with important implications for economic growth and development. We find that higher academic achievement reduces the willingness of young Kenyan women to appropriate others’ labor income, and shifts players toward a 50–50 split norm in a modified dictator game. This study demonstrates that education may have long-run impacts on social preferences, norms and institutions beyond the human capital directly produced.

Reputation systems aim to induce honest behavior in online trade by providing information about past conduct of users. Online reputation, however, is not directly connected to a person, but only to the virtual identity of that person. Users can therefore shed a negative reputation by creating a new account. We study the effects of such identity changes on the efficiency of reputation systems. We compare two markets in which we exogenously vary whether sellers can erase their rating profile and start over as new sellers. Buyer trust and seller trustworthiness decrease significantly when sellers can erase their ratings. With identity changes, trust is particularly low towards new sellers since buyers cannot discriminate between truly new sellers and opportunistic sellers who changed their identity. Nevertheless, we observe positive returns on buyer investment under the reputation system with identity changes, and our evidence suggests that trustworthiness is higher than in the complete absence of a reputation system.

We replicate Andreoni (Quarterly Journal of Economics 110: 1–21, 1995)’s finding that agents behave more selfishly when taking from a public account than when giving to a public good. Based on a neutral language setting we add new insights into motivations to give or take in a linear public good setting: we find that Andreoni’s result is partly driven by the complete elimination of giving options in the taking frame. However, a pure extension of the action space into the taking domain also leads to a significant increase in selfish behavior.

We use time, rather than money, as the salient component of subjects’ incentives in three workhorse experimental paradigms. The use of waiting time can be interpreted as a special type of real effort condition, in which it is particularly straightforward to achieve experimental control over incentives. The three experiments, commonly employed to study social preferences, are the dictator game, the ultimatum game and the trust game. All subjects in a session earn the same participation fee, but their choices affect the time at which they are permitted to leave the laboratory. Decisions that are associated with greater own payoff translate into the right to depart earlier. The modal proposal in both the dictator and ultimatum games is an equal split of the waiting time. In the trust game, there is substantial trust and reciprocity. Overall, social preferences are evident in time allocation decisions. We compare subjects’ decisions over time and money and find no significant differences in average decisions. The pattern of results suggests that results obtained in the laboratory with money as the medium of reward generalize to other reward media.

Incentivized methods for eliciting subjective probabilities in economic experiments present the subject with risky choices that encourage truthful reporting. We discuss the most prominent elicitation methods and their underlying assumptions, provide theoretical comparisons and give a new justification for the quadratic scoring rule. On the empirical side, we survey the performance of these elicitation methods in actual experiments, considering also practical issues of implementation such as order effects, hedging, and different ways of presenting probabilities and payment schemes to experimental subjects. We end with a discussion of the trade-offs involved in using incentives for belief elicitation and some guidelines for implementation.

This paper examines the relationship between norm enforcement and in-group favouritism behaviour. Using a new two-stage allocation experiment with punishments, we investigate whether in-group favouritism is considered as a social norm in itself or as a violation of a different norm, such as egalitarian norm. We find that which norm of behaviour is enforced depends on who the punisher is. If the punishers belong to the in-group, in-group favouritism is considered a norm and it does not get punished. If the punishers belong to the out-group, in-group favouritism is frequently punished. If the punishers belong to no group and merely observe in-group favouritism (the third-party), they do not seem to care sufficiently to be willing to punish this behaviour. Our results shed a new light on the effectiveness of altruistic norm enforcement when group identities are taken into account and help to explain why in-group favouritism is widespread across societies.

This paper studies the dynamics by which individuals with heterogeneous preferences partition themselves into groups. A novel experimental environment is developed to capture the tension between increasing returns to group size and attaining a group policy closest to an ideal point. Subjects can move freely between locations, with group policy either fixed by location or determined by member vote. A primary goal is to assess which of two stability concepts common to the group formation literature predicts which groups agents sort into. The same set of Nash stable partitions exist in each condition, with the efficient, strong Nash stable state requiring subjects to form heterogeneous groups and compromise on policy. I find that subjects who are only able to move between locations with fixed policies always over-segregate, rather than build efficient heterogeneous groups. When mobility is combined with the ability to vote on local policy, most subjects reach the efficient partition. This shows outcomes cannot be determined by considering the existence of stable states alone and that consideration must also be given to subtle aspects of the system dynamics. Further, it suggests that experiments may play an important role in understanding these group formation dynamics.