Experimental evidence on the relationship between perceived ambiguity and likelihood insensitivity

The Distribution of Ambiguity Attitudes

The adoption and use of mobile phone in rural China: A case study of Hubei, China

This thesis had two major aims: the first was aimed to test the efficacy of an Individual Cognitive Behavior Therapy for treatment of unipolar mood disorders with suicidal behavior and the second was to evaluate the risk and protective factors for suicidal behavior among patients with unipolar mood disorders in Malaysia. A review of literature on suicidal behavior in Malaysia suggested that lack of suicidal behavior-related measurements has been hindrance in identification of the risk and protective factors for suicidal behaviors. In addition, the investigation of variables that predicts treatment outcomes for patients with unipolar mood disorders with suicidal behavior has also beenhampered. This review chapter (Chapter 2; parts of them have been published in Comprehensive Psychiatry, 2014 and The Scientific World Journal, 2014) sets the scene for the following empirical chapters.Since most of the instruments used are not validated in Malaysia, thus the next 4 chapters validated two measuring instruments of risk factors and two measuring instruments for protective factors for suicidal behavior (other fours measures were not included as chapters due to limitation in words allowed in this thesis). The validated instruments and other measures were used to identify the risk and protective factors for suicidal behavior as well as to test the efficacy of Individual Cognitive Behavior Therapy (ICBT) for patients with unipolar mood disorders with suicidal behavior.Chapter 3, on Positive and Negative Suicide Ideation (PANSI) Inventory (submitted for publication), Chapter 4, on Beck Hopelessness Scale (BHS), Chapter 5, on Satisfaction With Life Scale (SWLS; published in Comprehensive Psychiatry, 2014), and Chapter 6, is on Reasons For Living Inventory (RFL; published in Comprehensive Psychiatry, 2014). The Exploratory and Confirmatory Factor Analyses were used to examine the psychometric properties and to establish the reliability and validity of these instruments. These measures were validated using the sample size of 483 from both medical and psychiatry patients. All the measures were found to have good reliability and validity using the exploratory and confirmatory factor analyses.Chapter 7 compared the two groups and the results showed that psychiatry patients had significantly higher mean scores on risk factors (hopelessness, psychological distress, depressive, anxiety and stress symptoms) and lower mean scores on protective factors (reasons for living, self esteem, hopefulness, satisfaction with life and social support) for suicidal behavior as compared to medical patients. In addition, patients with suicidal ideation had significantly higher mean scores on risk factors and lower mean scores on protective factors for suicidal behavior as compared to patients without suicidal ideation. And finally, there was a significant interaction between diagnosis (psychiatry patients with suicidal ideation, psychiatry patients without suicidal ideation, medical patients with suicidal ideation and medical patients without suicidal ideation) and suicidal behavior (suicidal ideation).Chapter 8 is a controlled trial comparing the Treatment As Usual (TAU) (N=36) with TAU + Individual Cognitive Behavior Therapy (ICBT) (TAU+ICBT) (N=36) groups. All the outpatients were diagnosed as suffering from unipolar mood disorders with suicidal ideation according to DSM IV-TR criteria. Eight sessions of manualised ICBT were given and each session lasted for 90 minutes. The measures of depressive symptoms (BDI-T and DASS-D), measures of suicidal ideation symptoms (PANSI-T and BSS-T), measures of risk factors for suicidal behavior (DASS-T, DASS-D, BHS-T, DASS-A, DASS-S) and measures of protective factors for suicidal behavior (RFL-T, RSE-T, AHTS-T, PRS-T, SWLS-T, PSR-FR, PSR-FM, SCB, MO, RF, FS, FSD, and CC) were administered at pre, mid, post, 3 months follow-up and 6 months follow-up for both groups. The TAU groups received outpatient treatment as usual by the psychiatrists of the hospital. The results showed that the TAU+ICBT groups consistently and significantly scored better on most of measures when compared to the TAU group. In addition, the TAU+ICBT group improved at earlier stage and the rate of improvement was significantly faster than the TAU group. The TAU group had significant improvement on seven dependent measures only. Thus the addition of the ICBT to TAU produced a more generalized and significant improvement on all the measures of depressive symptoms, measures of suicide ideation symptoms, measures of risk and protective factors of unipolar mood disordered with suicidal ideation patients.The general discussion of the whole thesis was presented in chapter 9, which ties together all the major significant findings from the previous chapters in the general context. The first empirical chapters on assessments were discussed and provided the base for discussions of chapter seven on psychopathology of mood disordered patients with suicidal behavior. Following that the findings of controlled trial on Individual Cognitive Behavioral Therapy of unipolar mood disorders with suicidal ideation in Malaysia was discussed and put in the general context of literature. The discussions were concluded with several strengths of this thesis, limitations of the studies and directions for future research.

Floods are one of the most lethal natural hazards. Recent studies show that in a large percentage of flood-related fatalities, victims engage in risk-taking behavior by getting deliberately in contact with floodwaters. This study integrates behavioral psychology and situational environmental factors with the aim to examine why individuals undertake such risky behavior. In particular, we draw on the theory of planned behavior (TPB) to link water depth perception with the intention of car drivers to enter floodwaters. The hypotheses on which the study was based were that the depth of the water adversely affects the driver’s intention to enter floodwaters, and that this effect is mediated by a behavior-favorable attitude, a behavior-favorable subjective norm, and perceived behavioral control. Further, to understand the conditions under which this process works, the moderating role of past behavior in the above relationships is also examined. Results from an experimental study (n = 1940) show that water depth perception affects intention. Attitude, perceived behavioral control, and normative beliefs operate as the underlying psychological mechanism that leads to the mitigation of intention in higher water depth situations. Interestingly, past risk-taking behavior is found to be a significant condition under which this process works, by mostly affecting individuals’ attitudes. Mediation and moderated mediation analyses were conducted to estimate causal relationships. The findings provide evidence of the significant interaction that environmental, psychological, and precedent behavioral factors have on behavioral intentions.

The first paper of this dissertation in Chapter II, “Insurance for Technology Adoption: An Experimental Evaluation of Schemes and Subsidies with Maize Farmers in Mexico”, analyzes experimentally how bundling the purchase of a risky technology, namely a higher yielding maize seed variety, with different insurance schemes, affects the total take-up of that variety. In this regard, the paper looks at the effects of (1) partial insurance versus full insurance, (2) geographical versus local basis risk, and (3) fair versus below-fair premium. This is the first paper to evaluate insurance schemes with different levels of risk reduction, basis risk and premium subsidies regarding their effect on technology adoption. The results add to the debate on insurance serving as a potential tool for incentivizing agricultural producers to adopt more productive, but more risky technologies, and thereby enabling them to escape poverty (Carter et al. 2016; Fan et al. 2013; Lybbert and Carter 2014; Nicola 2015; World Bank 2013). The second paper in Chapter III, “The Relationship between Farmers’ Shock Experiences and their Uncertainty Preferences - Experimental Evidence from Mexico” addresses the relationship between farmers’ uncertainty preferences, sociodemographic characteristics and their experience of adverse harvest shocks. Uncertainty preferences refer to a range of preference parameters as derived from Cumulative Prospect Theory (Kahneman and Tversky 1979; Tversky and Kahneman 1992), namely risk aversion, loss aversion and probability weighting, as well as ambiguity aversion (Ellsberg 1961). A series of incentivized lottery games are used to estimate these parameters with the sample of Mexican maize farmers, controlling for (1) sociodemographic characteristics and (2) the severity of experienced maize harvest losses. While there are several field studies examining the effect of shocks on risk preferences with subjects from developing countries, only few look at preferences beyond Expected Utility Theory and take into account Cumulative Prospect Theory, and none has looked at ambiguity aversion. Therefore, this paper sheds light on the role that the experience of adverse random shocks, as well as a range of sociodemographic variables, have in explaining one’s uncertainty preferences. The third paper in Chapter IV, “Formal Insurance, Risk Sharing, and the Dynamics of Other-Regarding Preferences”, analyzes how selectively providing formal insurance to members of a risk sharing network affects informal transfers and, subsequently, the dynamics of other-regarding preferences within that network. Many poor households in developing countries are excluded from formal financial markets and therefore rely on the mutual exchange within informal risk sharing networks to protect themselves against adverse income shocks. Social interactions in the aftermath of such shocks have been found to strengthen the social ties among members of these networks, while formal insurance has been found to crowd-out these transfers. Similarly, this third paper finds that when some members of risk sharing networks become formally insured, it affects the informal exchange of transfers among members, as well as their other-regarding preferences. This is the first study to explore the effect of insurance on other-regarding preferences in that context. In order to do so, an incentivized, three-stage experimental design with a baseline and an ex-post measurement of altruism, trust and trustworthiness through dictator and trust games is implemented with random and anonymous groups of three. Between the baseline and the ex-post measurement, a solidarity game is played with the same anonymous groups as in the ex-post measurement of other-regarding preferences, during which the shock structure and the availability of formal insurance are varied exogenously. The findings suggest that the effect of insurance depends on (1) the covariance structure of shocks and (2) is different for the insured and non-insured members within a network. Insurance either decreases trust levels of the uninsured or increases trust levels of the insured subjects towards the other network members, depending on whether the shocks affects one or more than one network member at a time. Trustworthiness and altruism remain unaffected by insurance. Furthermore, the analysis indicates that the results are driven by a change in the dynamics of the transfer behavior within the network induced by formal insurance. Specifically, there is evidence that subjects increase trust levels towards their network members after receiving higher transfers relative to the maximum possible value from them, but not after receiving higher transfers in absolute terms.

Local stress in the vicinity of the propagating cleavage crack tip in ferritic steel

Work-Relatedness.

The literature discusses risk aversion as one of the behavioral determinants of technology adoption. However, little attention has been paid to measuring ambiguity aversion of poor people in developing countries or in finding the role of ambiguity aversion in technology adoption. Risk experiments in the previous studies have been designed in such a way that individuals face the risky and/or ambiguous situations alone. Individuals in the real world, especially farmers in developing countries, are likely to get information from peers before making any decision regarding a new innovation that has an ambiguous nature. This paper addresses two broad issues. The first issue is to measure the risk and ambiguity preferences of Bangladeshi rural farmers. The paper investigates whether the attitudes toward uncertainty (risk and ambiguity) differ when farmers face the uncertainty alone versus when they are allowed to communicate with peer groups of 3 or 6. It also investigates whether farmers’ demographic characteristics affect their attitudes toward uncertainty or not. A second issue is to find whether measures of attitudes toward uncertainty is same across different groups of subjects using experimental lotteries. To do so, this paper replicates the same experiments with groups of students in two universities in Bangladesh. Finally, the paper also investigates whether demographic variables affect the attitudes toward risk and ambiguity aversion or not. It finds that risk attitudes of farmers and students are same when deciding alone. However, farmers tend to show higher variation in risk aversion than students sample when deciding in a group of 3. In the latter case, farmers tend to show less risk aversion than students. While disaggregating the measured risk attitudes across gender, female students tend to show more risk aversion as well as higher variation in risk aversion than male students in the sample. The study also finds that The study also finds that students’ and farmers’ demographic characteristics affect both risk and ambiguity aversion.

A new mixed agent-based network and compartmental simulation framework for joint modeling of related infectious diseases- application to sexually transmitted infections.

Oral health is a multidimensional concept, shaped by biological, behavioral, social, and structural factors, and represents a fundamental element of overall health and wellbeing 1 . Even though dental caries remains one of the most prevalent oral diseases worldwide, it reflects only one aspect of broader inequalities in oral health. These are influenced by unequal distribution of resources, opportunities, and health awareness 2 . Amongst these factors, parental education level and socioeconomic status stand out as key factors that significantly influence the course of oral health in children 3 . Families with low levels of education or limited socioeconomic resources often face cumulative obstacles, including low levels of oral health awareness, limited access to preventive dental services, and increased exposure to unhealthy environments 4,5 . These social factors not only shape oral hygiene behaviors and dietary habits, but also determine the family's ability to cope with health systems and adopt preventive practices, thus perpetuating intergenerational inequalities 2,6 .Despite strong evidence linking parental education, socioeconomic status and oral health outcomes, the mechanisms by which these factors operate are still not adequately covered in the global public health discourse 3 . The differences between countries highlight the structural nature of these inequalities, underscoring the need for comprehensive, system-wide strategies to promote health equity 7,8 . This editorial brings together emerging evidence from diverse settings to illustrate how parental education and socioeconomic status act as overarching determinants of children's oral health. Rather than summarizing individual contributions in isolation, the editorial critically analyzes common themes, identifies persistent knowledge gaps, and considers their implications for public health policy, preventive dentistry, and health equity initiatives.Across all the included studies, a consistent pattern emerges linking parental knowledge, social support structures, socioeconomic conditions, broader social determinants, and children's oral health outcomes. Taken together, the evidence reinforces the central role of families and contextual factors, as described in conceptual models of oral health inequalities, in shaping caries experience, hygiene behaviors, service utilization, and developmental conditions affecting teeth. health status and related behaviors. Higher health literacy and family socioeconomic status were strongly associated with better oral health outcomes, while gender-based differences reflected variations in societal expectations and health communication.These findings reinforce the influence of cultural and educational determinants on adolescent oral health and are consistent with global evidence highlighting the interaction between social context and health behaviors.The studies included in this research topic reveal several interconnected themes, reinforcing the interrelated nature of the determinants of children's oral health. First, parental education and health literacy consistently emerge as key factors influencing children's daily oral hygiene practices, dietary choices, and engagement with preventive dental services. Whether it is social support, knowledge of how to access services, or awareness of appropriate feeding and hygiene behaviors, parental capabilities strongly predict children's oral health outcomes. Second, socioeconomic disadvantage exacerbates barriers to preventive care and healthy behaviors. As low socioeconomic status is associated with higher prevalence of dental caries, suboptimal nutritional practices, reduced access to services, and increased risk of developmental conditions such as MIH. These patterns reflect global evidence showing that inequalities in oral health follow clear social gradients across different countries and health systems. Third, studies highlight the importance of integrated policies and public health interventions, particularly those delivered through schools and family centered programs.Interventions that combine oral health education, nutritional counseling, and structured parental support show promising effectiveness in mitigating inequalities when integrated within broader social and health frameworks.These findings collectively confirm that oral health is shaped by multi-level interactions involving individual behaviors, family dynamics, community resources, and national policy environments. They also underscore that improving children's oral health requires addressing both structural and behavioral factors simultaneously.The body of evidence underscores the need to align oral health promotion with parentcentered educational strategies, particularly during early childhood when health habits This research topic clearly demonstrates that improving children's oral health cannot be achieved through clinical services alone. Sustainable progress requires addressing the educational, behavioral, and socioeconomic foundations that shape oral health from a young age. By integrating parental education, addressing social inequalities, and incorporating preventive strategies into community and school systems, health professionals and policymakers can contribute to reducing disparities and promoting lifelong oral health.

Behavioral sleep curtailment is increasingly common in modern society and affects all age groups. In this article, we summarize the epidemiological and experimental evidence that has rapidly accumulated during the past 15 years to suggest that short sleep is a behavioral and environmental risk factor for obesity, alongside with increased caloric intake and decreased physical activity. It becomes important to inform the general population and the health professionals about the importance of getting enough sleep to stay lean.

Effects of communication, group selection, and social learning on risk and ambiguity attitudes: Experimental evidence from Bangladesh

In many circumstances, evaluations are based on empirical data. However, some observations may be imprecise, meaning that it is not entirely clear what occurred in them. We address the question of how beliefs are formed in these situations. The individual in our model is essentially a “frequentist.” He first makes a subjective judgment about the occurrence of the event for each imprecise observation. This may be any number between zero and one. He then evaluates the event by its “subjective” frequency of occurrence. Our model connects the method of processing imprecise observations with the individual's attitude toward ambiguity. An individual who in imprecise observations puts low (high) weight on the possibility that an event occurred is ambiguity averse (loving). An experiment supports the main assertions of the model: with precise data, subjects behave as if there were no ambiguity, whereas with imprecise data subjects turn out to be ambiguity averse.This paper was accepted by Brad Barber, Teck Ho, and Terrance Odean, special issue editors.

Conditional cooperation in case of a global public good – Experimental evidence from climate change mitigation in Beijing

We study information aggregation in a dynamic trading model. We show theoretically that separable securities, introduced by Ostrovsky in the context of Expected Utility, no longer aggregate information if some traders have imprecise beliefs and are ambiguity averse. Moreover, these securities are prone to manipulation as the degree of information aggregation can be influenced by the initial price set by the uninformed market maker. These observations are also confirmed in our laboratory experiment using prediction markets. We define a new class of strongly separable securities, which are robust to the above considerations and show that they characterize information aggregation in both strategic and non-strategic environments. We derive several testable predictions, which we are able to confirm in the laboratory. Finally, we show theoretically that strongly separable securities are both sufficient and necessary for information aggregation but, strikingly, there does not exist a security that is strongly separable for all information structures.