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Following the economic theory of averting behaviour, this thesis examines preferences for drinking water in Canada. Probabilistic mortality risk perceptions and other perceived water quality measures are included in econometric models of choice, and assessed for their impact, and value. The perceived risk variable is tested for adherence to the theoretical prediction of proportionality in risk reduction values. Data were gathered through an online survey where individuals reported water quality perceptions, mortality risk perceptions and expenditures on drinking water. Risk perceptions were gathered using a risk ladder. Resulting models suggested the existence of two classes within the Canadian population. A risk-sensitive class produced a significant coefficient on the perceived mortality risk variable. A second, risk-insensitive, non-compensatory class did not produce a significant risk coefficient, and analysis suggests that these individuals primarily consume tap water. Contrary to theoretical predictions, tests for proportionality suggest favourability of models with non-linear coefficients on risk variables. / Agricultural and Resources Economics

This dissertation consists of three essays that examine consumer behavior with respect to drinking water quality issues. The first essay uses contingent valuation method to explore consumers' willingness to pay (WTP) for a hypothetical material in home drinking water infrastructure that will remain leak free. Willingness to pay is investigated using both dichotomous choice and dichotomous choice with follow-up formats using a national telephone survey of consumers. Our results indicate that consumers' concerns about future system failures and income positively affect their WTP for an improved material while satisfaction with the water quality, education and the bid amount asked negatively affect their WTP for an improved material. There are no significant differences in the determinants of WTP between respondents who have experienced problems with home water infrastructure and respondents who have not. Furthermore, the estimated mean WTP does not change significantly between the dichotomous choice questioning format and the dichotomous choice with follow-up format The second essay investigates the determinants of consumers' willingness to accept improvement programs for three drinking water issues: water quality, pinhole leaks in home plumbing infrastructure and aging public infrastructure. The research is based on a mail survey of consumers in Northern Virginia and the Maryland suburbs of Washington D.C. The analysis focuses on the relationship between information, risk perceptions and willingness to pay. Results indicate that the choice to support any of the programs is negatively affected by the cost of the proposed improvement. Consumers' risk perceptions, the external information provided in the survey and whether they read the annual report from their water utility affect their choices for investment in improvement programs. The third essay examines the effect of risk perceptions about tap water, general risk aversion and consumers' characteristics on their decision to avert drinking water risks and related expenditures. Results are based on the same survey data from the second study. The risk aversion measure is elicited using the sequence of questions employed in the National Panel Study of Income Dynamics. Results indicate that consumers' risk perceptions affect both the decision to avert and the amount spent on averting activities. However, we do not find a significant impact of risk aversion on averting behavior. In addition we find that respondents were more likely to use water treatments if they were unsatisfied with their tap water or had problems or concerns with water odor and particles. / Ph. D.

This dissertation is composed of three essays investigating three aspects of future water issues. The first essay focuses on an examination of water scarcity issues caused by rapid population growth and economic development in Texas. The second essay examines water scarcity under climate change scenarios in Texas. The third essay discusses arsenic-related water quality issues in the drinking water. An integrated economic, hydrological, and environmental model is developed for the first two essays by implicitly incorporating uncertainty about future climate, water demand from all types of water use, a spatial river flow relationship, interaction between ground and surface water, institutional regulations, and the possibilities of inter-basin water transfers (IBTs). In studying water scarcity under economic growth and population growth, we find that while some cities and counties have sufficient water, there are some other cities and counties (especially Dallas, Fort Worth and Austin) facing different degrees of water scarcity problems. In studying the climate change impact, four Global Circulation Models (GCMs) with three Special Report on Emissions Scenarios (SRESs) yield consistent results. Water scarcity becomes even more severe for cities. Texas realizes slight gains in earlier periods and a net loss beginning in 2060. This study finds that twelve IBTs, if there is no climate change, and fourteen IBTs, under the climate change scenario, will be economically feasible in 2060. These IBTs can not only greatly reduce water scarcity, but also create new growth opportunity for Houston. Water is transferred from in-stream flow in source basins. There is no significant impact on other sectors except in-stream flow and water flow out to bay. In the third essay, a two-stage structural model is developed to model household risk-averting behavior with respect to arsenic-related mortality risk in the drinking water. The empirical results suggest that risk perceptions for the parents and children are important in the decision of how much to spend on water treatment, but not in whether or not to treat water. Parents in our sample displayed mixed altruism. The information generated by this dissertation can help state agencies to manage water resources and to improve water-related human health, especially health for children, more effectively and more efficiently.

Point of this diploma thesis is analyzing of three railroad crossing controlled by institutions of South-Moravian region, which are chosen by author. For analysis were chosen problematic railroad crossing where happened in last five years traffic accidents with consequences of death. Next criterion of choosing was type of security device. Chosen railroads crossing are representing all types of normally used security devices. That is why was chose railroad crossing with only warning crosses, light security device and last one with light security device with barrier beam. Theoretical part aims on: Basic parameters, dividing, numbering, system of function and marking of railroad crossing. In practical part, there are used mathematical calculations for assessment of safety on chosen railroad crossing and for determination of possibilities of averting a collision of both participants. Corrective measures are made for each railroad crossing taking to account it’s financial conditions. For each railroad crossing is made polygon with help of program Virtual Crash 3.

People with hearing loss (HL) often express a desire for the particular hearing device that will yield the best speech recognition. The problem with fulfilling that desire is that a vast number of hearing devices are available from which to choose. In recent years, medical device regulatory agencies have generally viewed hearing devices (i.e., hearing aids), particularly the hardware and even the software, as substantially equivalent. The purpose of this manuscript is to: 1) Synthesize a number of variables about the person, environment in which hearing occurs, as well as characteristics of the hearing aids that can impact speech recognition. 2) Describe a created tool entitled Realistic Expectations 2 (RE2), which has application to the clinical needs of estimating expected speech recognition with and without hearing aids. RE2 is available as a supplemental file to this manuscript and may be useful for comparing estimates against measures of speech recognition ability in addition to assisting with the explanation of the operation and limitations of hearing aids. When expected speech recognition is achieved, subsequent development of speech and language can continue based on circumstance, cognitive status, and cultural-specific learning, as well as personal and societal betterment efforts like education, rehabilitation, and therapy.