M. Vittoria Levati

Leading by Example in a Public Goods Experiment with Heterogeneity and Incomplete Information.

We study the effects of leadership on the private provision of a public good when group members are heterogeneously endowed. Leadership is implemented as a sequential public goods game where one group member contributes first and all the others follow. Our results show that the presence of a leader increases average contribution levels but less so than in case of homogeneous endowments. Leadership is almost ineffective, though, if participants do not know the distribution of endowments. Granting the leaders exclusion power does not lead to significantly higher contributions.

On the Social Dimension of Time and Risk Preferences: An Experimental Study

We report on an experiment designed to explore the interrelation of other-regarding concerns with attitudes towards risk and delay when the latter have a social dimension, i.e., pertain to ones own and another persons payoffs. For this sake, we compare evaluations of several prospects, each of which allocates either certain or risky and either immediate or delayed payoffs to the actor and to another participant. We find that individuals are mainly self-oriented as to social allocation of risk and delay, although they are other-regarding with respect to expected payoff levels.

On the Coevolution of Retribution and Trustworthiness: An (Indirect) Evolutionary and Experimental Analysis

Standard economic explanations of good conduct in trade rely almost exclusively on future-directed extrinsic motivations induced by material incentives. But intrinsic motives to behave trustworthily and to punish untrustworthiness do support trade. In our model, intrinsically motivated players are aware of their own type and observe the population share of other types. The material success of various types and their coevolution are analyzed, and it is checked whether the dynamics of the indirect evolutionary analysis are replicated in the laboratory.

Is Satisficing Absorbable? An Experimental Study

We experimentally investigate whether the satisficing approach is absorbable, that is, whether it still applies when participants become aware of it. In a setting where an investor decides between a riskless bond and either one or two risky assets, we familiarize participants with the satisficing calculus applied to specific portfolio selection tasks. After experimenting with this calculus repeatedly, participants can either continue using it or select their portfolio freely. The results reveal some absorbability of the satisficing approach in the simpler two-state setting, whereas more complexity renders the satisficing heuristics more difficult and their absorption less likely.

The Impact of Payoff Interdependence on Trust and Trustworthiness

Abstract In one-shot investment games where each player’s payoff is a convex combination of own and other’s profit, we measure trust by the amount given to the trustee and trustworthiness by the amount returned to the trustor by the trustee. Does the degree of payoff interdependence increase both trust and trustworthiness or one but not the other or neither of them? According to our experimental data, trust remains unaffected by the extent of interdependence whereas trustworthiness reacts positively to it.

DEADLINE EFFECTS IN SEQUENTIAL BARGAINING — AN EXPERIMENTAL STUDY

This paper reports on an experiment designed to explore the robustness of the deadline effect in multi period bargaining games using constant and decreasing pies, different time horizons, and constant and alternating roles. Our results indicate that decreasing pies and alternating roles lead to earlier agreements (i.e., attenuate the deadline effect) although only alternating roles significantly reduce the number of conflicts.

Are conditional cooperators willing to forgo efficiency gains? Evidence from a public goods experiment

We use a two-person public goods experiment to investigate how much agents value conditional cooperation when symmetric positive contributions entail efficiency losses. Asymmetric marginal per capita returns allow only the high-productivity player to increase group payoffs when contributing positive amounts. Asymmetric contributions, however, yield unequal individual payoffs. To assess a priori cooperative preferences, we measure individual ‘value-orientations’ by means of the decomposed game technique. We find that contributions remain negligible throughout the experiment, suggesting that people are not willing to contribute positive amounts if this may lead to damage efficiency.

Let Me See You! A Video Experiment on the Social Dimension of Risk Preferences

Previous studies have shown that decision makers are less other-regarding when their own payoff is risky than when it is sure. Empirical observations also indicate that people care more about identifiable than unidentifiable others. In this paper, we report on an experiment designed to explore whether rendering the other identifiable - via a short speechless video - can affect the relation between other-regarding concerns and attitudes toward social risk. For this sake, we elicit risk attitudes under two treatments differing in whether the actor can see the other or not. We find that seeing the other does not affect behavior significantly: regardless of the treatment, individuals are mainly self-oriented as to social allocation of risk, though they are other-regarding with respect to expected payoff levels.

Explaining Private Provision of Public Goods by Conditional Cooperation: An Indirect Evolutionary Approach

We adopt an indirect evolutionary approach to investigate whether and when conditional cooperation can explain the voluntary contribution phenomenon often observed in public goods experiments and in real life. Formally, conditional cooperation is captured by a guilt parameter describing how much an individual feels guilty about contributing less than the average. We find that the evolutionary stability of conditional cooperation depends on what is known about the (individual) guilt parameter of other group members.

Satisficing search versus aspiration adaptation in sales competition: experimental evidence

In a duopoly market, aspiration levels express how much sellers want to earn given their expectations about the other’s behavior. We augment the sellers’ decision task by eliciting their profit aspiration. In a first experimental phase, whenever satisficing is not possible, sales choices, point beliefs, or aspiration levels have to be adapted. This allows us to compare “aspiration-based satisficing” to “aspiration adaptation”. In a second phase, testing the absorption of satisficing, participants are free to select non-satisficing sales profiles. The results reveal that most participants are satisficers who, in line with aspiration adaptation theory, tend to adjust aspiration levels and to keep sales behavior nearly unchanged.