Ambiguity aversion: the explanatory power of indeterminate probabilities

Daniel Ellsberg presented in Ellsberg (The Quarterly Journal of Economics 75:643–669, 1961) various examples questioning the thesis that decision making under uncertainty can be reduced to decision making under risk. These examples constitute one of the main challenges to the received view on the foundations of decision theory offered by Leonard Savage in Savage (1972). Craig Fox and Amos Tversky have, nevertheless, offered an indirect defense of Savage. They provided in Fox and Tversky (1995) an explanation of Ellsberg’s two-color problem in terms of a psychological effect: ambiguity aversion. The ‘comparative ignorance’ hypothesis articulates how this effect works and explains why it is important to an understanding of the typical pattern of responses associated with Ellsberg’s two-color problem. In the first part of this article we challenge Fox and Tversky’s explanation. We present first an experiment that extends Ellsberg’s two-color problem where certain predictions of the comparative ignorance hypothesis are not confirmed. In addition the hypothesis seems unable to explain how the subjects resolve trade-offs between security and expected pay-off when vagueness is present. Ellsberg offered an explanation of the typical behavior elicited by his examples in terms of these trade-offs and in section three we offer a model of Ellsberg’s trade-offs. The model takes seriously the role of imprecise probabilities in explaining Ellsberg’s phenomenon. The so-called three-color problem was also considered in Fox and Tversky (1995). We argue that Fox and Tversky’s analysis of this case breaks a symmetry with their analysis of the two-color problem. We propose a unified treatment of both problems and we present a experiment that confirms our hypothesis.     

On quoting the empty expression

Roy Sorensen has argued that a certain technical use of quotation marks to name the empty string supports a revised version of Davidson’s theory of quotation. I point out that Sorensen’s considerations provide no support for Davidson’s original theory, and I show that at best they support the revised Davidsonian theory only to the same extent that they support a simpler revised version of a Tarskian theory.     

Cognitive biases and decision making in gambling

Heuristics and cognitive biases can occur in reasoning and decision making. Some of them are very common in gamblers (illusion of control, representativeness, availability, etc.). Structural characteristics and functioning of games of chance favor the appearance of these biases. Two experiments were conducted with nonpathological gamblers. The first experiment was a game of dice with wagers. In the second experiment, the participants played two bingo games. Specific rules of the games favored the appearance of cognitive bias (illusion of control) and heuristics (representativeness and availability) and influence on the bets. Results and implications for gambling are discussed.     

Life satisfaction and perception of happiness among university students

The aim of this essay has been the evaluation of three orientations towards happiness: pleasure, meaning and engagement, as well as their relation to life satisfaction and the perception of happiness in a sample of 320 university students. The results show that the most used kind of orientation towards happiness is pleasure, followed by meaning, and finally engagement. It has also been found that pleasure is the orientation most closely associated to happiness while engagement seems to be more related to life satisfaction. These findings aim to the distinction between the concepts of happiness and life satisfaction and lead the attention to the actions which can improve the levels of happiness.     

Barriers perceived by teachers at work, coping strategies, self-efficacy and burnout

This study examines the relationships among stressors, coping strategies, self-efficacy and burnout in a sample of 724 Spanish primary and secondary teachers. We understood stressors as barriers perceived by teachers that interfere with their work meeting learning objectives and which cause them stress and burnout. An analysis of teacher responses using hierarchical regression revealed that pedagogical barriers had significant positive effects on the burnout dimensions. Furthermore, the results show not only the moderator role played by coping strategies in the pedagogical barriers-burnout dimensions relationship, but also the association between self-efficacy and the coping strategies used by teachers. Practical implications are discussed.     

Stability of the factor structure of Barrat's Impulsivity Scales for children across cultures: a comparison of Spain and Colombia

Despite the great importance of impulsivity in many childhood and adolescence disorders, there are few self-reports on child impulsivity. Recently, a modified version of Barratt's BIS-11 questionnaire adapted for children has been developed, which may be useful in assessing this personality dimension. The present study reports an adaptation of this questionnaire in a different culture (Colombia) and assesses the degree of convergence between the factor structures of both adaptations using consensus oblimin rotation. The results indicate not only that the factor structure of the test remains stable across both adaptations, and that two of the three scales in the Colombian version show acceptable reliabilities, but also that cultural and linguistic issues are important in test adaptation even when the same language is used.     

Development and validation of a questionnaire about the main variables affecting the individual investor's behavior in the Stock Exchange

Development and validation of a questionnaire about the main variables affecting the individual investor's behavior in the Stock Exchange. There is a considerable lack of information about the methodology usually used in most of the studies about individual investor's behavior. The studies reviewed do not show the method used in the selection of the items or the psychometric properties of the questionnaires. Because of the importance of investment in the Stock Exchange nowadays, it seems relevant to obtain a reliable instrument to understand individual investor's behavior in the Stock Exchange. Therefore, the goal of the present work is to validate a questionnaire about the main variables involved in individual investors' behavior in the Stock Exchange. Based on previous studies, we elaborated a questionnaire using the Delphi methodology with a group of experts. The internal consistency (Cronbach alpha=.934) and validity evidence of the questionnaire show that it may be an effective instrument and can be applied with some assurance.