Understanding Cumulative Risk Perception from Judgments and Choices: An Application to Flood Risks

Catastrophic events, such as floods, earthquakes, hurricanes, and tsunamis, are rare, yet the cumulative risk of each event occurring at least once over an extended time period can be substantial. In this work, we assess the perception of cumulative flood risks, how those perceptions affect the choice of insurance, and whether perceptions and choices are influenced by cumulative risk information. We find that participants' cumulative risk judgments are well represented by a bimodal distribution, with a group that severely underestimates the risk and a group that moderately overestimates it. Individuals who underestimate cumulative risks make more risk‐seeking choices compared to those who overestimate cumulative risks. Providing explicit cumulative risk information for relevant time periods, as opposed to annual probabilities, is an inexpensive and effective way to improve both the perception of cumulative risk and the choices people make to protect against that risk.     

Peer Crowd Affiliation and Internalizing Distress in Childhood and Adolescence: A Longitudinal Follow‐Back Study

Concurrent and longitudinal associations between peer crowd affiliation and internalized distress were examined in a sample of 246 youth (148 girls, 98 boys). Children completed measures of depression, social anxiety, loneliness, and self‐esteem when they were in grades 4 to 6 (Time 1), and again 6 years later during adolescence (grades 10 – 12; Time 2). At Time 2, adolescents also reported their self‐concept and their identification with reputation‐based peer crowds, including Populars, Jocks, Brains, Burnouts, Non‐Conformists, and None/Average crowds. Results indicated that adolescents' report of peer crowd affiliation was concurrently associated with self‐concept and levels of internalizing distress. Follow‐back analyses of internalizing trajectories revealed that Populars/Jocks had experienced significant declines in internalizing distress across development, whereas Brains exhibited some increases in internalizing distress between childhood and adolescence.     

A Bayesian Hierarchical Model for the Evaluation of a Website

Consider a website and the surfers visiting its pages. A typical issue of interest, for example while monitoring an advertising campaign, concerns whether a specific page has been designed successfully, i.e. is able to attract surfers or address them to other pages within the site. We assume that the surfing behaviour is fully described by the transition probabilities from one page to another, so that a clickstream (sequence of consecutively visited pages) can be viewed as a finite-state-space Markov chain. We then implement a variety of hierarchical prior distributions on the multivariate logits of the transition probabilities and define, for each page, a content effect and a link effect. The former measures the attractiveness of the page due to its contents, while the latter signals its ability to suggest further interesting links within the site. Moreover, we define an additional effect, representing overall page success, which incorporates both effects previously described. Using WinBUGS, we provide estimates and credible intervals for each of the above effects and rank pages accordingly.     

A comparison of approaches for estimating the effect of women's education on the probability of using modern contraceptive methods in Malawi

The aim of this study is to estimate the effect of education on the probability of married Malawian women using modern contraceptive methods by accounting for both observed and unobserved confounders. We conduct a sensitivity analysis and compare the results of naive models with instrumental variable models to account for the potential endogeneity of education. Our findings demonstrate conflicting results between the two modelling approaches. The naive models report smaller education effects on the probability of using modern contraceptive methods compared to instrumental variable models. We also find that by relaxing the functional form assumption on the effect of continuous covariates, using a flexible instrumental variable model, the education's effect follows a positive, nonlinear pattern. This finding is not observed with a classic instrumental variable model.     

Modified chain sampling plans for lot inspection by variables and attributes

The purpose of acceptance sampling is to develop decision rules to accept or reject production lots based on sample data. When testing is destructive or expensive, dependent sampling procedures cumulate results from several preceding lots. This chaining of past lot results reduces the required size of the samples. A large part of these procedures only chain past lot results when defects are found in the current sample. However, such selective use of past lot results only achieves a limited reduction of sample sizes. In this article, a modified approach for chaining past lot results is proposed that is less selective in its use of quality history and, as a result, requires a smaller sample size than the one required for commonly used dependent sampling procedures, such as multiple dependent sampling plans and chain sampling plans of Dodge. The proposed plans are applicable for inspection by attributes and inspection by variables. Several properties of their operating characteristic-curves are derived, and search procedures are given to select such modified chain sampling plans by using the two-point method.     

Preverbal Infants' Ability to Encode the Outcome of Distributive Actions

This research examined whether 10‐month‐old infants expect agents to perform equal distribution of resources. In Experiment 1, infants saw a distributor performing either an equal distribution where one strawberry was given to each of two recipients, or an unequal distribution that favored one of the recipients. Infants looked longer at the unequal test event, suggesting that they expected the strawberries to be distributed equally. In Experiment 2, the potential recipients were replaced with inanimate objects to rule out a lower‐level alternative explanation of the results in Experiment 1 based on symmetric movement of the distributor. Infants' looking times did not reveal a preference for one of the two outcomes of the test events (i.e., symmetric or asymmetric movement). Experiment 3 controlled for the role of the distributive action, that is, here the distributors only removed barriers revealing strawberries that the recipients already had. No preference was observed when an equal or unequal initial allocation of resources was revealed. Experiment 4 assessed whether infants relied on affiliative information provided by the distributor's movements. The distributor made the same movements as in Experiment 1, but without distributing any strawberries, and no difference in looking times was observed. These findings support the view that preverbal infants expect agents to behave according to a simple principle: Resources are to be distributed equally among equivalent recipients. We discuss the possible links between such reactions and the emergence of an early sense of fairness.     

Testing for Serial Independence: Beyond the Portmanteau Approach

Portmanteau tests are typically used to test serial independence even if, by construction, they are generally powerful only in presence of pairwise dependence between lagged variables. In this article, we present a simple statistic defining a new serial independence test, which is able to detect more general forms of dependence. In particular, differently from the Portmanteau tests, the resulting test is powerful also under a dependent process characterized by pairwise independence. A diagram, based on p-values from the proposed test, is introduced to investigate serial dependence. Finally, the effectiveness of the proposal is evaluated in a simulation study and with an application on financial data. Both show that the new test, used in synergy with the existing ones, helps in the identification of the true data-generating process. Supplementary materials for this article are available online.     

Are We Educating Creative Professionals? The Results of Some Experiments on the Education of Social Work Students in Italy

Creativity is a competence crucial for the practice of social work. In particular, it is associated with a greater ability to solve complex problems and to learn, and it is considered to be an integral element of the professional identity of social workers. Nevertheless, in the past 20 years, neoliberal policies and bureaucratization have promoted models of education focused more on technical skills than on imaginative and ideational capacities. This article presents the results of two experiments conducted to determine the effects on creativity and imagination of the technical education of social workers. The results show that creativity is not a variable independent of the type of education delivered to students and that educational programmes which emphasise only the technical dimension of social work can have a direct influence on the creative abilities of students. It is therefore necessary to strike the right balance between education aimed at the acquisition of technical skills and education that promotes creativity.