Two experiments show that violations of expected utility due to ambiguity, found in general decision experiments, also affect belief aggregation. Hence we use modern ambiguity theories to analyze belief aggregation, thus obtaining more refined and empirically more valid results than traditional...

This article develops a new approach to study the impact on beliefs and decisions of uncertain probability forecasts by advisors. The core concept of that approach, which builds on the revealed-preference approach favored by economists, is the one of revealed beliefs - the precise probability...

In an experimental setting, we applied a dual strategy to better understand the effect of pictures of eyes on human behavior. First, we investigated whether the effect of eyes was limited to interaction tasks in which the subjects' decisions influenced the outcomes of other subjects. We expanded...

Many important decisions are made without precise information about the probabilities of the outcomes. In such situations, individual ambiguity attitudes influence decision making. The present study identifies affective states as a transient cause of ambiguity attitudes. We conducted two...

We propose simple behavioral definitions of comparative uncertainty aversion for a single agent towards different sources of uncertainty. Our definitions allow for the comparison of utility curvature towards different sources if the agent's choices satisfy subjective expected utility towards...

In this paper, we build on the emerging literature on group decision-making to study the so-called ‘group shift’ effect, i.e., groups are less risk-averse than individuals. Our study complements past research in two ways. First, we study the group shift effect under two sources of...

Internal capital models are increasingly used across the insurance business, including reinsurance optimization, risk appetite and business planning. While this expansion is well documented, less is known about what modelers do in practice, in order to embed capital models within their...

We address the question as to whether judgmental overconfidence, as assessed by probability miscalibration, is related to positive illusions about the self. We first demonstrate that judgmental overconfidence measured with interval production procedures can be considered a trait, due to...

Most decision-making research in economics focuses on individual decisions. Yet, we know, from psychological research in particular, that individual preferences can be sensitive to social pressures. In this paper, we study the impact of a group environment on individual preferences for risky...