Trust, communication and equlibrium behaviour in public goods

This paper reports a novel cross-cultural public goods game experiment played in real time through Internet. Web-based software was used to compare the contributions to public good of different groups of participants: mixed, consisting of both Italians (students in law and economics) and Russians (students in economics), as well as all-Italian and all-Russian groups. This setup allows for testing for a number of effects, including participants’ awareness of the group composition in terms of nationality and gender of group members; possibility of coordination of one’s strategy during a cheap talk session organized before some of the games was used as an additional control. Our results show that the degree of cooperation is rather high, but does not vary significantly with nationalities of the group members, while communication tends to enhance contributions to public goods. A notable difference between the subjects representing the two nations is an overly strong and increasing cooperativeness of the Russian female participants in contrast to that of the Russian men, as well as the Italians.PUBLIC GOODS GAME, CROSS-CULTURAL EXPERIMENT, COOPERATION

Resting-State Theta Oscillations and Reward Sensitivity in Risk Taking

Females demonstrate greater risk aversion than males on a variety of tasks, but the underlying neurobiological basis is still unclear. We studied how theta (4–7 Hz) oscillations at rest related to three different measures of risk taking. Thirty-five participants (15 females) completed the Bomb Risk Elicitation Task (BRET), which allowed us to measure risk taking during an economic game. The Domain-Specific Risk-Taking Scale (DOSPERT) was used to measure self-assessed risk attitudes as well as reward and punishment sensitivities. In addition, the Barratt Impulsiveness Scale (BIS11) was included to quantify impulsiveness. To obtain measures of frontal theta asymmetry and frontal theta power, we used magnetoencephalography (MEG) acquired prior to task completion, while participants were at rest. Frontal theta asymmetry correlated with average risk taking during the game but only in the female sample. By contrast, frontal theta power correlated with risk taking as well as with measures of reward and punishment sensitivity in the joint sample. Importantly, we showed that reward sensitivity mediated a correlation between risk taking and the power of theta oscillations localized to the anterior cingulate cortex. In addition, we observed significant sex differences in source- and sensor-space theta power, risk taking during the game, and reward sensitivity. Our findings suggest that sensitivity to rewards, associated with resting-state theta oscillations in the anterior cingulate cortex, is a trait that potentially contributes to sex differences in risk taking

Off the charts: massive unexplained heterogeneity in a global study of ambiguity attitudes

Ambiguity attitudes have been indicated as important determinants of economic outcomes in economic models, but we still know little about the demographic correlates of ambiguity attitudes, or indeed about the universality of patterns found in the West. We analyse the ambiguity attitudes of almost 3000 students across 30 countries. For gains we find ambiguity aversion everywhere, while ambiguity aversion is much weaker for losses. We also find ambiguity attitudes to systematically change with probabilities for both gains and losses, reflecting ambiguity-insensitivity to probabilities. Much of the between-country variation can be explained through a few macroeconomic characteristics. In contrast, we find massive unexplained variation at the individual level, suggesting that individual differences in ambiguity attitudes remain difficult to explain. We also find much unexplained heterogeneity in individual responses to different decision tasks. We conclude by discussing potential issues underlying this heterogeneity, and indicating potential solution

Protocol & Instructions

Materials and methods for our study are reported here. The experimenter script was followed by researchers conducting experimental sessions. The experiment protocol reports methodological and procedural aspects relative to the preparation and execution of the experiment. Instructions and questionnaire report the materials administered to participants