Proper scoring rules are scoring methods that incentivize honest reporting of subjective probabilities, where an agent strictly maximizes his expected score by reporting his true belief. The implicit assumption behind proper scoring rules is that agents are risk neutral. Such an assumption is often unrealistic when agents are human beings. Modern theories of choice under uncertainty based on rank-dependent utilities assert that human beings weight nonlinear utilities using decision weights, which are differences between weighting functions applied to cumulative probabilities.

In this paper, I investigate the reporting behavior of an agent with a rank-dependent utility when he is rewarded using a proper scoring rule tailored to his utility function. I show that such an agent misreports his true belief by reporting a vector of decision weights. My findings thus highlight the risk of utilizing proper scoring rules without prior knowledge about all the components that drive an agent’s attitude towards uncertainty. On the positive side, I discuss how tailored proper scoring rules can effectively elicit weighting functions. Moreover, I show how to obtain an agent’s true belief from his misreported belief once the weighting functions are known.

This study provides the first comprehensive analysis of individual perceptions of tail risks. It focuses not only on the probability, as has been studied by Nicholas Barberis and others, but also on anticipation of damage. We examine how those perceptions relate to experts’ estimates and publicly available risk information. Behavioural factors—availability bias, threshold models of choice, worry and trust—are found to have a significant impact on risk perceptions. The probability of tail events is overestimated, which is consistent with probability weighting in prospect theory. Potential damage is underestimated, one reason why individuals do not invest in protective measures.

Myrseth and Wollbrant (2015) offer an alternative theoretical explanation for our finding that defection entails more cognitive conflict than cooperation (Kieslich & Hilbig, 2014). Although we completely agree that different theoretical explanations for a result are possible, we maintain that the theoretical approach we tested (Rand et al., 2014) is parsimonious and falsifiable, excluding certain plausible results a priori. By comparison, the alternative framework proposed by Myrseth and Wollbrant requires several debatable assumptions to account for our findings, rendering it the more complex theory. Besides, their framework as a whole could have accounted for any possible finding in our experiment, making it impossible to falsify it with our data. We thus conclude that the notion by Rand et al.—that there is a spontaneous disposition to cooperate—has more empirical content while requiring fewer assumptions.

Whether it pertains to the foods to buy when one is on a diet, the items to take along to the beach on one’s day off or (perish the thought) the belongings to save from one’s burning house, choice is ubiquitous. We aim to determine from choices the criteria individuals use when they select objects from among a set of candidates. In order to do so we employ a mixture IRT (item-response theory) model that capitalizes on the insights that objects are chosen more often the better they meet the choice criteria and that the use of different criteria is reflected in inter-individual selection differences. The model is found to account for the inter-individual selection differences for 10 ad hoc and goal-derived categories. Its parameters can be related to selection criteria that are frequently thought of in the context of these categories. These results suggest that mixture IRT models allow one to infer from mere choice behavior the criteria individuals used to select/discard objects. Potential applications of mixture IRT models in other judgment and decision making contexts are discussed.

The concept of “passive risk taking”, which refers to the risk brought on or magnified by inaction, has recently appeared in the literature on risk taking. Keinan and Bereby-Meyer (2012) have developed a scale to measure the personal tendency for passive risk taking (PRT); the scale has criterion validity and high test-retest reliability; it correlates with reported passive risk taking in everyday life and with the DOSPERT scale. Furthermore, it presents divergent validity from classic risk-taking constructs such as sensation seeking, and convergent validity with procrastination and avoidance. In this paper we propose a validation of the PRT scale in Italian. We performed the linguistic adaptation to Italian via the five steps suggested by Guillemin and colleagues (1993) and Beaton and colleagues (2000); we then submitted the derived questionnaire to a 297-adult sample. Results show that two out of three factors from the original scale were confirmed. However the third factor, originally composed of 6 items, was not consistent. We present the scale derived from such results, and discuss the differences with the original scale.

Genetic testing for breast and ovarian cancer can help target prevention programs, and possibly reduce morbidity and mortality. A positive result of BRCA1/2 is a substantial risk factor for breast and ovarian cancer, and its detection often leads to risk reduction interventions such as increased screening, prophylactic mastectomy and oophorectomy. We examined predictors of the decision to undergo cancer related genetic testing: perceived risk, family risk of breast or ovarian cancer, and numeracy as predictors of the decision to test among women at high risk of breast cancer. Stepwise regression analysis of survey responses from 459 women registered in the Cancer Genetics Network revealed greater likelihood to test for women with more family history, higher perceived risk of mutation, or Ashkenazi descent. Neither subjective nor objective numeracy was associated with the decision to test, although we replicated an earlier finding that subjective numeracy predicted willingness to pay for testing. Findings underscore the need for genetic counselling that disentangles risk perception from objective information to promote better decision-making in the context of genetic testing. Highlighting these factors is crucial for public health campaigns, as well as to clinic-based testing and direct-to-consumer testing.

Using capture-recapture analysis we estimate the effective size of the active Amazon Mechanical Turk (MTurk) population that a typical laboratory can access to be about 7,300 workers. We also estimate that the time taken for half of the workers to leave the MTurk pool and be replaced is about 7 months. Each laboratory has its own population pool which overlaps, often extensively, with the hundreds of other laboratories using MTurk. Our estimate is based on a sample of 114,460 completed sessions from 33,408 unique participants and 689 sessions across seven laboratories in the US, Europe, and Australia from January 2012 to March 2015.

This study investigates the psychometric characteristics of the General Decision-Making Scale (GDMS) on a sample of Slovak high-school and university students. Secondly, it addresses the relationship between decision-making styles and a) decision making competencies and b) mental health as validity criteria. Participants were 427 Slovak high school and university students (64.6% females). The GDMS showed a good internal consistency and its original factor structure was confirmed. Low but significant relationships between the decision-making styles were found. Two decision-making styles served as significant predictors of the general decision-making competency (avoidant and spontaneous) and another two were found to predict mental health. The intuitive decision-making style was a protective factor and the avoidant style was a risk factor.

There is an increased willingness to help identified individuals rather than non-identified, and the effect of identifiability is mainly present when a single individual rather than a group is presented. However, identifiability and singularity effects have thus far not been manipulated orthogonally. The present research uses a joint evaluation approach to examine the relative contribution of identifiability and singularity in moral decision-making reflecting conflicting values between deontology and consequentialism. As in trolley dilemmas subjects could either choose to stay with the default option, i.e., giving a potentially life-saving vaccine to a single child, or to actively choose to deny the single child the vaccine in favor of five other children. Identifiability of the single child and the group of children was varied between-subjects in a 2x2 factorial design. In total 1,232 subjects from Sweden and the United States participated in three separate experiments. Across all treatments, in all three experiments, 32.6% of the subjects chose to stay with the deontological default option instead of actively choosing to maximize benefits. Results show that identifiability does not always have a positive effect on decisions in allocation dilemmas. For single targets, identifiability had a negative or no effect in two out of three experiments, while for the group of targets identifiability had a more stable positive effect on subjects’ willingness to allocate vaccines. When the effect of identifiability was negative, process data showed that this effect was mediated by emotional reactance. Hence, the results show that the influence of identifiability is more complex than it has been previously portrayed in the literature on charitable giving.

In motor lotteries the probability of success is inherent in a person’s ability to make a speeded pointing movement. By contrast, in traditional economic lotteries, the probability of success is explicitly stated. Decision making with economic lotteries has revealed many violations of rational decision making models. However, with motor lotteries people’s performance is often near optimal, and is well described by statistical decision theory. We report the results of an experiment testing whether motor planning decisions exhibit the attraction effect, a well-known axiomatic violation of some rational decision models. The effect occurs when changing the composition of a choice set alters preferences between its members. We provide the first demonstration that people do exhibit the attraction effect when choosing between motor lotteries. We also found that people exhibited a similar sized attraction effect in motor and traditional economic paradigms. People’s near-optimal performance with motor lotteries is characterized by the efficiency of their decisions. In attraction effect experiments performance is instead characterized by the violation of an axiom. We discuss the extent that axiomatic and efficiency measures can provide insight in assessing the rationality of decision making.