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Assessments of chemical health risks are performed by scientific experts. Their intended use is as bases for decisions. This thesis tries to answer the questions of how uncertainty is, and should be, communicated in such risk assessments. The thesis consists of two articles and an introductory essay. Article I focuses on the linguistic aspect of the communication of uncertainty in risk assessments. The aim of the article is to elucidate how risk assessors actually indicate uncertainty in risk assessment reports. Because of the prevalent uncertainty in risk assessment, deriving from several sources, uncertainty is communicated in verbal, rather than numerical terms. A typology of uncertainty indicators – phrases used to express uncertainty – is proposed and applied to the reviewed reports. It is found that the use of such phrases is not transparent, and the article concludes by a number of recommendations for improving the practice. Article II mainly deals with the content of the communication. The overall question treated is what a characterization of uncertainty should include if a decision made on the basis of the risk assessment information is to be as well-founded as possible. A set of conditions is put forward to be fulfilled by a characterization of uncertainty if it is to be adequate from a decision-making point of view. The greater part of the introductory essay is devoted to the concept of uncertainty which, at the conceptual level, does not appear to have been much discussed by philosophers / QC 20101208

Due to an increasing demand from decision makers for proper economic evaluations of health care services, cost-effectiveness analyses are becoming increasingly frequent. The statistic of interest in cost-effectiveness analysis is the incremental cost effectiveness ratio (ICER). When patient-specific data on costs and effects of alternative interventions is available, it can be used to quantify the uncertainty in the estimate of the ICER. Expressing this uncertainty by using confidence intervals has been recommended. However, because the statistic of interest is a ratio of two correlated random variables, its variance cannot be estimated exactly. Furthermore, the distribution of the ratio is unknown. Recently, several approximate methods have been proposed for calculating confidence intervals for the incremental cost-effectiveness ratio. These include two parametric methods: one which relies on a Taylor's Series approximation of the variance, and one based on Fieller's theorem; as well as a number of methods which rely on bootstrapping methodology. In this manuscript, these methods were applied to data obtained from a randomized clinical trial in which both health resources consumed and health outcomes were observed. Furthermore, several variations of the bootstrapping methods were proposed and applied to the same data set. Probabilities of the true ICER being in given ranges were also estimated using a bootstrapping approach. Finally, issues of sample size and power were briefly considered. The relative advantages and disadvantages of the different approaches were discussed. / Thesis / Master of Science (MS)

The EPA recently completed a major study to evaluate exposure and risk associated with a primary contaminant, radon and its progeny in drinking water (EPA, 1995). This work resulted in the development of a Monte Carlo Simulation model written in the programming language C. The model developed by the EPA has been used to estimate the cancer fatality risk from radon in water for exposed populations served by community ground water supplies, and to provide a quantitative analysis of the uncertainty associated with the calculations (EPA, 1995). This research is a continuation of the study conducted by the EPA. In this project, a Monte Carlo computer model will be developed to evaluate the risk associated with exposure to volatile compounds in drinking water. The model will be based on a computer program (developed previously by the EPA) for estimating the risks associated with exposure to radon in drinking water. The model will be re-implemented in the form of a computer program written in C. The analysis for radon will be extended to include the entire range of contaminants found in drinking water supplies. The initial focus of the project has been on extending the analysis to cover the ingestion exposure pathway for volatile compounds, but ultimately the risk via ingestion and dermal sorption will also be evaluated. The integrated model can estimate the risks associated with various levels of contaminants in drinking water and should prove valuable in establishing Maximum Contaminant Levels (MCLs) for the entire range of contaminants found in water supplies and generated in water treatment and distribution systems. / Master of Science

This dissertation extends contemporary views about uncertainty. It does so through a reading of the role of uncertainty in the political thought of two modern philosophers, Baruch Spinoza and David Hume. Despite uncertainty's notable and multi-disciplinary appeal in the academic literature, the frame in which most scholars think about social and political uncertainty is one-sided. On the whole, contemporary scholars consider uncertainty as a problem in need of a remedy. In the social sciences uncertainty is transformed into risk in order to empirically calculate risk probabilities. The hope is that risks (uncertainties) can be controlled, reduced, and in all, mitigated. In this dissertation, I argue for a conceptual rethinking of uncertainty that expands its scope and reach to include a socially and politically beneficent understanding, a constructive form of uncertainty. In particular, I explore the ways social groups experience conditions of uncertainty in different contexts through an examination of what I term future-oriented and epistemic uncertainty in Hume and Spinoza's political thought. Spinoza's arguments for liberal democracy, and Hume's arguments favoring commercial society, are highlighted as instances of constructive uncertainty. The dissertation concludes by applying a general understanding of constructive uncertainty to the ideology of the American Dream in order to illustrate suggestively how a constructive conception of uncertainty might prove useful when critically engaging contemporary matters. / Ph. D.

Yes / This paper uses precarity as a framework to understand the vulnerabilities experienced by those living with or caring for someone living with dementia. Drawing on qualitative interview data from the Improving the Experience of Dementia and Enhancing Active Life (IDEAL) programme, we attend to our participants' reflections on how they manage the condition and the wider circumstances in which this occurs. To interrogate the utility of precarity, we focus on our participants' descriptions of needs and challenges and set these alongside both the wider contexts in which they seek or offer care (formal and informal) and the sets of values attributed to different ways of living with dementia. Building on the work of Portacolone, our analysis identified four interconnected themes: uncertainty; experiences of support and services; independence and personhood; and cumulative pressures and concerns. We develop this analysis by reviewing how our themes reflect, extend, or depart from previously identified markers of precarity and consider the specific ways in which these markers shape the lives of those living with dementia. / ‘Improving the experience of Dementia and Enhancing Active Life: living well with dementia. The IDEAL study’ was funded jointly by the Economic and Social Research Council (ESRC) and the National Institute for Health and Care Research (NIHR) through grant ES/L001853/2. ESRC is part of UK Research and Innovation (UKRI). ‘Improving the experience of Dementia and Enhancing Active Life: a longitudinal perspective on living well with dementia. The IDEAL-2 study’ is funded by Alzheimer’s Society, grant number 348, AS-PR2-16-001.

This thesis analyzes investment incentives of strategic firms in industries where either demand is uncertain, or the good produced is economically non-storable and demand fluctuates. In those industries, investment is a long run decision, whereas production has to be adjusted short-run. Prominent examples are recently liberalized utilities such as the electricity sector. Regulated monopolies have been replaced by a small number of competing firms, which often are considered to behave strategically in order to exercise market power. Whereas the regulatory regimes prior to liberalization induced generous (over-)investment choices, we observe increasing unease of experts and policy makers regarding investment incentives in liberalized electricity markets. The first three chapters of this thesis (part one) analyze total capacity choice of strategic firms prior to producing for the spot market. We first determine the equilibrium of the market game. In the remainder of the first part we analyze the interdependency of enhanced spot market competition and firms overall capacity choice. We first analyze the impact of complete elimination of market power at the spot market giving rise to marginal cost pricing. We then consider the impact of price caps at the spot market. And finally we study the impact of reduced market power at the spot markets due to forward contracting. In the second part of the thesis firms can invest into several technologies. This allows them to determine not only their total capacity but also it's precise composition. In the absence of strategic interaction, for a single regulated firm, this has already been thoroughly analyzed in the so called peak load pricing literature, which has been widely applied for electricity markets prior to liberalization. In order to accommodate for the completely changed situation after liberalization, however, we extend this framework to the case of strategically interacting firms. Based on data of the German electricity market, we then illustrate and empirically quantify our theoretical results. We determine firms’ investment choices for different market structures and quantify the impact of spot market interventions on investment decisions and welfare. This allows us to quantify the potential for the exercise of market power, in the long run, when firms’ investment decisions are taken into account.

This study examined state-receiver apprehension and uncertainty as they relate to each other and to information seeking and confirmation of relational predictions in initial interactions.

Sustainable production and consumption have become more important internationally, which has led to the transformation of market structures and competitive situations into the direction of servitisation. This means that manufacturing companies are forced to compete through the supply of services as opposed to products. Particularly the suppliers of long-life products such as submarines and airplanes no longer simply sell these products but provide their capability or availability. Companies such as Rolls-Royce Engines achieve 60% of their revenue through selling a service rather than the engine itself. For a manufacturing company, the shift towards being a service provider means that they usually have to bid for service contracts, sometimes competitively. In the context of competitive bidding, the decision makers face various uncertainties that influence their decision. Ignoring these uncertainties or their influences can result in problems such as the generation of too little profit or even a loss or the exposure to financial risks. Raising the decision maker’s awareness of the uncertainties in the form of e.g. a decision matrix, expressing the trade-off between the probability of winning the contract and the probability of making a profit, aims at integrating these factors in the decision process. The outcome is to enable the bidding company to make a more informed decision. This was the focus of the research presented in this thesis. The aim of this research was to support the pricing decision by defining a process for modelling the influencing uncertainties and including them in a decision matrix depicting the trade-off between the probability of winning the contract and the probability of making a profit. Three empirical studies are described and the associated decision process and influencing uncertainties are discussed. Based on these studies, a conceptual framework was defined which depicts the influencing factors on a pricing decision at the bidding stage and the uncertainties within these. The framework was validated with a case study in contract bidding where the uncertainties were modelled and included in a decision matrix depicting the probability of winning the contract and the probability of making a profit. The main contributions of this research are the identification of the uncertainties influencing a pricing decision, the depiction of these in a conceptual framework, a method for ascertaining how to model these uncertainties and assessing the use of such an approach via an industrial case study.

High causally uncertain (CU) individuals experience lingering doubts about their ability to determine the causes of social events (Weary & Edwards, 1994). Furthermore, these people tend to perceive their interactions and conversational partners more negatively (Boucher & Jacobson, 2009). However, the reasons for these negative reactions remain unclear. Therefore, the purpose of the current set of studies was to explore two possible explanations for these reactions. Specifically, in three studies, I examined if insufficient uncertainty reduction or negative interpersonal expectations mediate the relationship between causal uncertainty and liking for a recent acquaintance. In Study 1 (N = 114), participants engaged in a brief unstructured dyadic conversation, whereas in Study 2 (N = 176), they engaged in three conversations with different partners. Finally, in Study 3 (N = 220), I examined the effects of temporarily activating causal uncertainty beliefs during initial interactions. As predicted, causal uncertainty was negatively associated with liking and uncertainty reduction. In Studies 1 and 2, high CU participants reported more uncertainty about themselves and their partner, and less liking than did low CU participants. Although chronic levels of causal uncertainty in Study 3 were not associated with liking or uncertainty reduction, participants who reported more current feelings of uncertainty also reported more uncertainty about themselves and their partner, and less liking. More importantly, uncertainty reduction fully mediated the effect of causal uncertainty on liking in Study 1 and partially mediated the effect of current uncertainty feelings on liking in Study 3. Therefore, high CU people’s negative social perceptions appear to stem, at least in part, from an inability to reduce their social uncertainty during initial interactions. In contrast, the relationship between causal uncertainty and interpersonal expectations remains unclear. Although causal uncertainty (as well as current uncertainty feelings) in Studies 1 and 3 were not associated with negative interpersonal expectations, high CU participants in Study 2 did report more negative expectations for their first conversation relative to low CU participants. Furthermore, although causal uncertainty was positively related to rejection sensitivity, rejection sensitivity was unable to account for the causal uncertainty effects on liking. / Thesis (Ph.D, Psychology) -- Queen's University, 2009-07-24 15:13:51.847