Multivariate forests with missing mixed outcomes

In this article, we propose a multivariate random forest method for multiple responses of mixed types with missing responses. Imputation is performed for each bootstrap sample used to build the individual trees that form the forest. The individual trees are built using a weighted splitting rule allowing downweighting of imputed observations. A simulation study shows the benefits of this approach over complete case analysis when missing responses are missing completely at random and missing at random (MAR). In particular, the gain in prediction accuracy of the proposed method is larger in the MAR case and also increases as the proportion of missing increases.     

Adolescent Electronic Media Use: Instead of Doing What?

Adolescents like to watch TV and listen to the radio, even on school days, but their day contains, like for all other people, only 24 hours. What do those who use electronic media frequently neglect? Data from 14- and 16-year-old adolescents from 12 European countries and from the USA (EURONET sample) were analyzed (N = 3,250). The correlations between time spent using electronic media (EM) and 15 other daily activities were all negative, which is not surprising given the fact that the sum of all activities is bound to be 24 hours. We, therefore, calculated correlations between electronic media use and the proportions of each other activity within the remaining time. A clear pattern emerged. The method allowed us to identify “mandatory” activities that always have high priority, such as sleeping and attending school, and “optional” activities that enter into competition with electronic media use, including engaging in sports, playing music, leisure reading, and being with friends without media use. As to the mandatory activities, the correlations between media-using time and the proportions of remaining time were positive; relative to the optional activities, the correlations between media-using time and the proportions of remaining time were negative. While one might expect school homework to be regarded as mandatory, the correlation patterns identified it as optional. As to the average electronic media-using times, there were marked differences not only between the individual participants, but also between the countries. While Bulgarian adolescents spent an average of 2.37 hours of a regular school day using electronic media, French adolescents averaged only 1.72 hours.     

Behavioral evidence for framing effects in the resolution of the doctrinal paradox

The aggregation of individual sets of judgments over interconnected propositions can yield inconsistent collective sets of judgments, even when the individual sets of judgments are themselves consistent. A doctrinal paradox occurs when majority voting on a compound proposition (such as a conjunction or disjunction) yields a different result than majority voting on each of the elements of the proposition. For example, when most individuals accept proposition X; most individuals accept proposition Y ; but only a minority of individuals accept the compound proposition ‘X and Y’. Conducting two elemental votes would lead to accept X and Y , but conducting one compound vote would lead to reject X and Y . In such a situation, do people manifest a stable preference as to which voting procedure should be applied? This research reports the results of two behavioral experiments using a within-participant design, which show that procedural preferences can be upturned by framing either positively or negatively the set of judgments to be aggregated. This shift in procedural preference leads to large swings in the final collective judgment endorsed by participants.     

A Note on Exponentially Smoothed Seasonal Differences

Filtering economic time series can be justified if variations within a certain frequency interval are relevant for the problem at hand. It is shown here that exponential smoothing of seasonal differences provides a simple means of damping short oscillations, including seasonal ones.     

Grandchild Care Transfers by Ageing Immigrants in France: Intra-household Allocation and Labour Market Implications

Using a unique sample on ageing first generation immigrants in France, we explore the distribution of grandchild care across offspring and the impact of this transfer on the labour supply of the mother. Our results indicate that grandchild care is spread unequally across siblings, and this inequality is driven more strongly by better labour market potential than by weaker financial status of the recipient. There is further evidence that even after accounting for potential endogeneity and unobserved heterogeneity, grandchild care has a positive impact on the labour supply of the mother. The pattern of intergenerational time transfers differs across people with different national and religions backgrounds.     

The impact of risk aversion and ambiguity aversion on annuity and saving choices

Journal of Risk and Uncertainty - We analyze the impact of risk aversion and ambiguity aversion on the competing demands for annuities and bequeathable savings using a lifecycle recursive utility...     

Does Perceived Social Support Buffer the Negative Effects of Type C Personality on Quality of Life of Breast Cancer Patients?

The present study investigated possible Type C personality–quality of life (QOL) relationship, and the moderating role of perceived social support in this relation among 101 postoperative breast cancer patients. Participants were from different cities in Turkey but receiving treatment in the capital, Ankara. Obtained data were analyzed by moderated regression analysis. According to the results, Type C personality was not related to the QOL of participants, however, higher perceived social support was associated with better QOL in patients. Also, perceived social support moderated Type C personality–QOL relation. Accordingly, patients high on Type C personality and perceived social support had the highest QOL. In contrast, patients high on Type C personality and low on perceived social support had the lowest QOL. Findings, as well as the strengths and limitations of the study, were discussed in the light of the relevant literature. As a possible clinical implication, enhancement of social support networks of the patients were suggested.     

Five legitimate definitions of correlated equilibrium in games with incomplete information

Aumann's (1987) theorem shows that correlated equilibrium is an expression of Bayesian rationality. We extend this result to games with incomplete information.First, we rely on Harsanyi's (1967) model and represent the underlying multiperson decision problem as a fixed game with imperfect information. We survey four definitions of correlated equilibrium which have appeared in the literature. We show that these definitions are not equivalent to each other. We prove that one of them fits Aumann's framework; the agents normal form correlated equilibrium is an expression of Bayesian rationality in games with incomplete information.We also follow a universal Bayesian approach based on Mertens and Zamir's (1985) construction of the universal beliefs space. Hierarchies of beliefs over independent variables (states of nature) and dependent variables (actions) are then constructed simultaneously. We establish that the universal set of Bayesian solutions satisfies another extension of Aumann's theorem.We get the following corollary: once the types of the players are not fixed by the model, the various definitions of correlated equilibrium previously considered are equivalent.