Does Experience Affect Fairness and Reciprocity in Lab Experiments?

Does Experience Affect Fairness and Reciprocity in Lab Experiments?

Date:	2016-07
By:	Tiziana Medda (University of Cagliari) Vittorio Pelligra (University of Cagliari) Tommaso Reggiani (LUMSA University)
URL:	http://d.repec.org/n?u=RePEc:lsa:wpaper:wpc09&r=net
	One of the most common criticisms about the external validity of lab experiments in economics concerns the representativeness of participants usually considered in these studies. The ever-increasing number of experiments and the prevalent location of research centers in university campuses produced a peculiar category of subjects: Students with high level of laboratory experience built through repeated participations in experimental sessions. We investigate whether the experience accumulated in this way biases subjects’ behaviour in a set of simple games widely used to study social preferences (Dictator Game, Ultimatum Game, Trust Game, and Prisoner’s Dilemma Game). Our main finding shows that subjects with a high level of experience in lab experiments do not behave in a significantly different way from novices.
Keywords:	Experimental Methodology, External Validity, Experience, Lab Experiment
JEL:	D03 D83 C91 C92

Individual and Group Preferences Over Risk: An Experiment

Individual and Group Preferences Over Risk: An Experiment

Date:	2016-07
By:	Morone, Andrea Temerario, Tiziana
URL:	http://d.repec.org/n?u=RePEc:pra:mprapa:72747&r=net
	The recent literature on individual and group choices over risk has led to different results. In some studies under unanimity, groups were found to be less risk averse than individuals, while those under majority did not highlight significant differences. However, both the types of studies impose the decision rule to the group. In the present work we elicited groups’ preference under risk using a consensus rule, i.e. groups are free to solve disagreement endogenously, just as in the real life. Results from our pairwise choices experiment shows that when group members are free to use any rule they want in order to reach unanimity, there is no statistical difference between individuals’ and groups’ risk aversion.
Keywords:	Risk; uncertainty; decision-making; group decision; lottery; experimental economics; experiment;
JEL:	C92 D81

Who are the voluntary leaders? Experimental evidence from a sequential contribution game

Who are the voluntary leaders? Experimental evidence from a sequential contribution game

Date:	2016
By:	Raphaële Préget (LAMETA – Laboratoire Montpelliérain d’Économie Théorique et Appliquée – Montpellier SupAgro – Centre international d’études supérieures en sciences agronomiques – UM3 – Université Paul-Valéry – Montpellier 3 – INRA Montpellier – Institut national de la recherche agronomique [Montpellier] – UM – Université de Montpellier – CNRS – Centre National de la Recherche Scientifique) Phu Nguyen Van (UMR Beta – CNRS – Centre National de la Recherche Scientifique) Marc Willinger (LAMETA – Laboratoire Montpelliérain d’Économie Théorique et Appliquée – Montpellier SupAgro – Centre international d’études supérieures en sciences agronomiques – UM3 – Université Paul-Valéry – Montpellier 3 – INRA Montpellier – Institut national de la recherche agronomique [Montpellier] – UM – Université de Montpellier – CNRS – Centre National de la Recherche Scientifique, Université de Montpellier)
URL:	http://d.repec.org/n?u=RePEc:hal:journl:hal-01300195&r=net
	We rely on the methodology of Fischbacher et al. (2001) in order to identify subjects’ behavioral types. We then link the likelihood to act as a leader in a repeated public goods game to the elicited behavioral types. The leader in a group is defined as the subject who voluntarily decides in the first place about his contribution. The leader’s contribution is then reported publicly to the remaining group members who take their contribution decisions simultaneously. Our main findings are that leaders emerge in almost all rounds and that subjects who are identified as conditional cooperators are more likely to act as leaders than other types, e.g. free-riders or triangle-contributors. We also find that voluntary leaders, irrespective of their behavioral type, contribute always more than followers. However the presence of leadership does not prevent the decay that is commonly observed in linear public goods experiments.
Keywords:	Voluntary Contribution Mechanism,Leadership,Public Goods,Experimental Economics

Risk and punishment revisited Errors in variables and in the lab

Risk and punishment revisited Errors in variables and in the lab

Date:	2016-07-26
By:	Christoph Engel (MPI for Research on Collective Goods, Bonn) Oliver Kirchkamp (School of Economics and Business Administration, Friedrich-Schiller-University Jena)
URL:	http://d.repec.org/n?u=RePEc:jrp:jrpwrp:2016-015&r=net
	We provide an example for an errors in variables problem which might be often neglected but which is quite common in lab experimental practice: In one task, attitude towards risk is measured, in another task participants behave in a way that can possibly be explained by their risk attitude. How should we deal with inconsistent behaviour in the risk task? Ignoring these observations entails two biases: An errors in variables bias and a selection bias. We argue that inconsistent observations should be exploited to address the errors in variables problem, which can easily be done within a Bayesian framework.
Keywords:	Risk, lab experiment, public good, errors in variables, Bayesian inference
JEL:	C91 D43 L41

A Note on Shapley Ratings in Brain Networks

A Note on Shapley Ratings in Brain Networks

Date:	2016
By:	Musegaas, Marieke (Tilburg University, Center For Economic Research) Dietzenbacher, Bas (Tilburg University, Center For Economic Research) Borm, Peter (Tilburg University, Center For Economic Research)
URL:	http://d.repec.org/n?u=RePEc:tiu:tiucen:3562c06a-1612-4d93-a299-4b939ea95c91&r=net
	We consider the problem of computing the in uence of a neuronal structure in a brain network. Abraham, Kotter, Krumnack, and Wanke (2006) computed this influence by using the Shapley value of a coalitional game corresponding to a directed network as a rating. Kotter, Reid, Krumnack, Wanke, and Sporns (2007) applied this rating to large-scale brain networks, in particular to the macaque visual cortex and the macaque prefrontal cortex. We introduce an alternative coalitional game that is more intuitive from a game theoretical point of view. We use the Shapley value of this game as an alternative rating to analyze the macaque brain networks and corroborate the findings of Kotter et al. (2007). Moreover, we show how missing information on the existence of certain connections can readily be incorporated into this game and the corresponding Shapley rating.
Keywords:	brain networks; coalitional games; Shapley value
JEL:	C71