Roger Berger

Bargaining Over Time in Ultimatum Game Experiments

We report the first ultimatum game experiment with bargaining over waiting time. The experiment was created to avoid effects of windfall gains. In contrast to donated money, time is not endowed by the experimenter and implies a natural loss to the subjects. This allows for a better measurement of the inherent conflict in the ultimatum game. We implemented three anonymity conditions; one baseline condition, one condition with anonymity among the subjects and one double-blind condition in which the experimenter did not know the division of waiting time. While we expected to observe less other-regarding behavior in ultimatum game bargaining over time, our experimental results rather confirm previous ultimatum game experiments, in which people bargained over money. The modal offer was half of the waiting time and only one offer was rejected. Interestingly, anonymity did not change the results significantly. In conclusion, our experiment confirms other-regarding behavior in the ultimatum game.

Should I Stay or Should I Go? Optimal Decision Making in Penalty Kicks.

Bar-Eli et al. (2007, hereafter BE) conclude that goalkeepers in football suffer from an action bias that preserves them from optimally playing in penalty kicks. Particularly, they are thought to jump too often to the sides and to stay too seldom in the centre. This bias is explained by a norm that goalkeepers should jump to the sides in order to minimize their mental costs when failing to stop the ball. Because in this case at least they have done something instead of just watching how the kicker converts the penalty. We show that these conclusions are wrong using the data set of BE, the data set of the criticized Chiappori et al. (2002), an own data set consisting of 1043 penalty kicks from the German Bundesliga and data of the likewise criticized Palacios-Huerta (2003). The crucial mistake of BE consists of modeling the strategic interaction between the players as if it was a parametric decision. A game theoretic analysis that takes into account the middle as an option shows that goalkeepers on average behave astoundingly close to their optimal choices. Therefore, the action bias BE identify in an enquiry of goalkeepers actually is a rule of thumb that helps the goalies to maximise the chance of stopping the penalty kick. Finally, it is shown that players are not only rational in choosing their sides in a sole penalty kick but also in a series of kicks.

Messung von studentischem Workload

Studentischer Workload ist eines der zentralen Konzepte von universitaren Curricula. Dennoch steckt dessen Messung noch in den Kinderschuhen. Hier wird eine Ubersicht zu den Methoden der Workloadmessung gegeben und die Ergebnisse eines Pilotprojekts berichtet, bei dem der Workload mit der Tagebuchmethode mit einem standardisierten Papier-Fragebogen und alternativ erstmalig auch mit einer Applikationssoftware (App) fur Smartphones oder Tablets gemessen wurde. Weiterhin werden auch pro- und retrospektive Einschatzungen des Workloads untersucht. Methodisch zeigt sich, dass die Tagebuchmethode die valideste Messung ergibt. Allerdings war der App-Fragebogen, der noch viel Entwicklungspotential aufweist, dafur weniger geeignet als die konventionelle Papierbroschure. Die Messung des Workloads uber eine retrospektive Einschatzung der letzten ein bis zwei Wochen konnte eine mogliche Alternative zu der aufwandigen Tagebucherhebung darstellen. Insgesamt zeigt sich, dass bei der Workloaderhebung noch viel methodologische Forschung notwendig ist. Der Beitrag schliest mit praktischen Hinweisen zur Durchfuhrung einer Workloaderhebung.

Reziprozität und Reputation

Dieser Beitrag gibt eine Ubersicht uber den aktuellen Forschungsstand zur Modellierung von Reziprozitat und Reputation. Er beginnt mit einer Begriffsklarung. Reziprozitat wird als ein gegenseitiger, konditionaler Austausch von Ressourcen definiert. Spezifischere Formen von Reziprozitat werden nach der Motivation, dem Adressaten und der Art des Austauschs unterschieden. Durch diese Kriterien konnen positive und negative, direkte und indirekte, sowie strategische und altruistische Reziprozitat unterschieden werden. Es werden auch synonyme Begriffspaare wie spezifische und generalisierte oder schwache und starke Reziprozitat besprochen und eingeordnet. Reputation wird in diesem Beitrag als eine spezifische Variante von indirekter Reziprozitat betrachtet, bei der die Information uber die vergangene Kooperationsneigung eines Akteurs von einem Dritten stammt.

Wild mammals as economic goods and implications for their conservation

In social-ecological systems, human activities and animal distribution are interrelated. Any effort at studying wildlife abundance therefore requires the integration of detailed socioeconomic context into species distribution models. Wild mammals have always been an important resource for humankind, and concepts of economic goods provide an analytical framework to deduce relevant socioeconomic factors that shape wild mammal–human relationships and consequences for the spatial distribution patterns of wild mammals. We estimated the effects of the human population on wild mammals in a rural area in the Republic of Guinea, West Africa. We related large mammal survey data via statistical models to detailed socioeconomic information about the human population in the same area. We compared models, taking account of the human population in different ways, and found that wild mammal abundance was better explained by human factors other than human population density. Although human population density had a negative effect on wild mammals, the effect of market integration and food taboos were more important and not accounted for by human population density alone. Additionally, the analysis did not provide evidence of higher mammal abundance in classified forests, which one would assume if conservation interventions aimed at reducing hunting were implemented. Beyond doubt, the relationship between humans and wild mammals is highly complex and speciesand context-specific. To understand mammal–human relationships in the wider context of social-ecological systems, an in-depth knowledge of the socioeconomic characteristics of a human population is needed to identify crucial links and driving mechanisms.

Fördern drohende Verluste Kooperation? / Do Looming Losses Foster Cooperation?

Zusammenfassung Aus der spieltheoretischen Analyse des einmaligen Gefangenendilemmas (PD) kann abgeleitet werden, dass Kooperation sowohl aufgrund aggressiver als auch aufgrund defensiver Motive unterbleibt. Dabei spielt es keine Rolle, ob in dem PD Verluste oder Gewinne verteilt werden. Aus dem Konzept der Verlustaversion folgt dagegen, dass in einem negativen PD, in dem Verluste verteilt werden, die Kooperation höher ausfallen sollte als in einem gleichwertigen positiven PD mit Gewinnauszahlungen. Szenarien und Dilemma-Situationen, in denen die entsprechenden Unterschiede von Bedeutung sein sollten, sind allgegenwärtig (z. B. Umweltprobleme, Kriege). In der präsentierten empirischen Evidenz aus Laborexperimenten mit 270 Studierenden zeigen sich jedoch keine Unterschiede in den Kooperationsraten zwischen Gewinn- und Verlustbereichen. Summary Game theoretical analysis of the one-shot prisoner’s dilemma (PD) predicts a reduction of cooperation due to both aggressive and defensive motives regardless of whether gains or losses are at stake. Loss aversion among the participants, in contrast, suggests that looming losses will foster cooperation. As a consequence, cooperation should be higher in a negative PD in the loss domain than in an equivalent positive PD in the gain domain. Scenarios and dilemma situations for which respective differences should be significant are ubiquitous (e.g. environmental problems, wars). Empirical evidence from laboratory experiments with 270 students, however, indicates no differences in cooperation rates between gain and loss domains.

Do Trained Actors Learn Strategic Behaviour or Are They Selected into Their Positions? Empirical Evidence from Penalty Kicking

This paper studies if the Minimax theorem holds for the behaviour of trained and untrained actors in the field. This is explored with data from 1043 football penalty kicks from professionals of the German Bundesliga and for 268 penalty kicks from untrained players. Minimax makes good predictions about the collective patterns emerging from the behaviour of experienced actors, as well as about their individual strategic actions. However, this is not true for untrained actors. In the next step it is explored if, the professional players learned their behaviour, or if they were selected into their roles because they had the required abilities. The data suggests that the professionals were selected by the competitive conditions of professional sports.

Effects of Suppression Policy in a Market for Heroin: A Natural Quasi-Experiment

This paper focuses on the observable market effects of a more severe suppression of hard drug supply by the police. After surveying 624 regular heroin users in the Swiss cities of Bern and Zurich in a standardized way, the suppression policy had been intensified in Bern. To study the consequences of the policy change, the survey was repeated in both cities which resulted in another 419 standardized interviews. The results of this natural quasi experiment suggest that a more repressive practice of law enforcement agencies does not necessarily have the intended effects for central variables (e.g., price and quality of drugs, number of drug dealers) at the retail level of the illicit market.

Rationalität beim Elfmeterschießen. Entscheiden sich Bundesligaspieler strategisch optimal

Rationalitat in der Entscheidungstheorie beinhaltet zwei Grundelemente: namlich rational sein zu wollen und gleichzeitig rational sein zu konnen. Technisch gesprochen bedeutet dies, dass ein rationaler Akteur sowohl vollstandig eigenorientierte Praferenzen als auch die Fahigkeit hat, unter den gegebenen Restriktionen seinen Nutzen zu maximieren.