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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Discrete choice analysis of preferences for dental prostheses

Zhang, Shanshan January 2014 (has links)
Background: Tooth loss has a negative impact on patients’ general health and wellbeing. Dental prostheses can restore oral function, aesthetics and improve oral health related quality of life. Preferences for dental prostheses cannot be fully captured using existing clinical studies and questionnaires. Discrete choice experiment (DCE) is a novel method in health economics to elicit people’s preference for treatments and it allows the researcher to integrate all aspects relevant to treatment into evaluation and measurement of interrelationship between factors. The aim of this PhD thesis is to use a mixed method of DCE and qualitative interviews to analyse dentists and patient’s preferences for dental prosthesis choices in replacing missing teeth. Methods: Discrete choice experiment questionnaires were developed, describing dental prosthdontic treatments in multi-dimensions, including outcome, process and economic factors. Survey and analysis using the questionnaires were conducted with dentists and patients in Edinburgh. Qualitative interviews with Edinburgh dentists and patients were carried out to derive factors to aid the DCE questionnaire design and provide in-depth understanding of DCE results. Systematic reviews were performed to summarise existing evidence on prosthesis evaluation in traditional quantitative studies and perception of prostheses in qualitative interviews. The current application of DCEs in dentistry was also systematically reviewed. Results: Treatment longevity was identified as the most important factor for dentists and patients’ treatment decisions of anterior missing tooth replacements, followed by appearance and chewing function. Dentists put more value on fixation/comfort and treatment procedure than patients. Patients cared about cost of treatment whereas dentists were relatively insensitive. Gender, age and treatment experience significantly influenced patients’ preference for treatment characteristics. Dental implant supported crown was preferred by dentists, whereas patients gave higher utility to traditional prosthodontic treatments. The monetary benefit of fixed dental prostheses ranged from £1856 -£3848 for patients, far exceeding their willingness-to-pay (WTP), which was £120 - £240. Dentists were willing to pay £600-£3000, more than the perceived benefit £503 to £1649. Qualitative study identified the above factors and provided interpretation of DCE results. Problems in the dental care system related to referral and training for dental implant treatments were raised. Discussion: This thesis is the first DCE application in dentistry evaluating and comparing dentists and patients preferences for missing tooth replacements. Dentists and patients’ preferences were elicited qualitatively and qualitatively integrating multidimensional factors. Patients’ preference for treatments, monetary benefit and WTP were demonstrated to be different from dentists’. Treatment benefits exceeded patients WTP for fixed dental prostheses.
12

Benefits of health care beyond health: an exploration of non-health outcomes of health care.

Haas, Marion Ruth January 2002 (has links)
Recent interest in identifying and measuring health outcomes represents an advance in our understanding of how health care for individuals should be evaluated. However, the concept of health outcomes has mainly focussed on improvements in health status. Non-health outcomes of health care may also be important to patients. In this thesis, four tasks were undertaken with the aim of identifying non-health outcomes and establishing the extent of their relevance and importance to patients. First, the illness experience literature was reviewed to identify potential non-health outcomes. Seven categories of non-health outcomes were identified: information, being treated with dignity, being able to trust the health care provider, having distress recognised and supported, participating in decision making, legitimation and reassurance. Second, to gain an in-depth understanding of these concepts, topic-specific literature was reviewed and synthesised. Third, in order to confirm how relevant and important the concepts were to patients, a qualitative study was conducted with each of two different groups of health service users. Broadly, patients considered that all the non-health concepts were relevant, although the extent to which they were important varied. Fourth, to test the relative importance of the seven concepts, a Stated Preference Discrete Choice experiment in the context of general practice was conducted. This study showed that most people thought their GP demonstrated behaviour likely to result in the production of non-health outcomes. The results showed that although all the non-health outcomes were, to some extent, preferred by respondents, trust was most important, followed by legitimation and recognition of and support for emotional distress. Once again, these results point to the importance of context in the evaluation of health care from the patient's perspective. While still being perceived as positive aspects of health care, the provision of information and acting autonomously or participating in decisions about their health care were the non-health outcomes considered least important by patients
13

Trust-Region Algorithms for Nonlinear Stochastic Programming and Mixed Logit Models

Bastin, Fabian 12 March 2004 (has links)
This work is concerned with the study of nonlinear nonconvex stochastic programming, in particular in the context of trust-region approaches. We first explore how to exploit the structure of multistage stochastic nonlinear programs with linear constraints, in the framework of primal-dual interior point methods. We next study consistency of sample average approximations (SAA) for general nonlinear stochastic programs. We also develop a new algorithm to solve the SAA problem, using the statistical inference information to reduce numercial costs, by means of an internal variable sample size strategy. We finally assess the numerical efficiency of the proposed method for the estimation of discrete choice models, more precisely mixed logit models, using our software AMLET, written for this purpose.
14

Canadian consumer valuation of farm animal welfare and quality verification the case of pork

Uzea, Adrian Daniel 07 July 2009
There is increasing pressure from animal rights organizations (AROs) on restaurant chains, food retailers, and meat processors to implement more stringent farm animal welfare (FAW) requirements for their suppliers. In the United States, AROs have recently initiated successful ballots to phase out confinement practices in several states. In Canada AROs have been pressuring both public and private sector stakeholders to improve FAW. Are FAW issues, however, paramount in the minds of Canadian consumers? Is the demand for more stringent FAW protocols primarily determined by a subset of consumers with very strong preferences or does it signal a more fundamental underlying change in consumer and societal preferences? Given the credence nature of FAW, who do consumers trust (i.e., government vs. private industry vs. independent third parties) in the market place for the provision of FAW quality assurances? What are the determinants of trust in these organizations for providing accurate information about animal welfare?<p> In order to answer these questions, a stated preference consumer survey encompassing FAW issues specific to the Canadian pork sector was tested on two samples of consumers in summer 2008, namely: a general population sample (GPS) across Canada and a sample of AROs members. Consumers participated in a purchase experiment where they had to chose between pork chops characterized by combinations of different levels of FAW attributes (i.e., housing system, gestation stalls, and use of antibiotics), quality verifying organization, and price. Multinomial Logit and Latent Class Logit Models were used to analyse the survey data.<p> Surprisingly, outdoor system does not seem to resonate well with Canadians, as both the GPS and the members of the AROs discounted this attribute. As expected, the AROs members have much stronger preferences for the other FAW attributes than have consumers in the GPS. Nevertheless, significant heterogeneity exists within consumer preferences. Five classes of consumers were identified in the GPS with respect to their preferences for FAW. At one end of the spectrum are the FAW sensitive consumers (12.3%) that have higher willingness-to-pay (WTP) for FAW, while at the other end of the spectrum Price Conscious consumers (18.3%) do not exhibit any WTP for FAW. The other three classes (69.4%) comprise respondents with mixed perceptions regarding FAW. Government and Third Party verification of FAW quality assurances had the strongest influence on consumers preferences in both samples. As well, scientific experts in FAW along with the above two organizations are the most credible in providing information about the welfare of pigs. The extent to which these organizations are knowledgeable about the welfare of pigs is the most important factor enhancing consumers trust. Results from this study suggest that there are potential marketing opportunities for pork chops sourced from pigs raised on farms where sows are kept in groups, and where credible quality assurances can be established, that private industry could consider. As well, the results suggest that consumers would derive benefits from the government taking a more active role with respect to validating FAW quality assurances.
15

An Integrated Two-stage Innovation Planning Model with Market Segmented Learning and Network Dynamics

Ferreira, Kevin D. 28 February 2013 (has links)
Innovation diffusion models have been studied extensively to forecast and explain the adoption process for new products or services. These models are often formulated using one of two approaches: The first, and most common is a macro-level approach that aggregates much of the market behaviour. An advantage of this method is that forecasts and other analyses may be performed with the necessity of estimating few parameters. The second is a micro-level approach that aims to utilize microeconomic information pertaining to the potential market and the innovation. The advantage of this methodology is that analyses allow for a direct understanding of how potential customers view the innovation. Nevertheless, when individuals are making adoption decisions, the reality of the situation is that the process consists of at least two stages: First, a potential adopter must become aware of the innovation; and second the aware individual must decide to adopt. Researchers, have studied multi-stage diffusion processes in the past, however a majority of these works employ a macro-level approach to model market flows. As a result, a direct understanding of how individuals value the innovation is lacking, making it impossible to utilize this information to model realistic word-of-mouth behaviour and other network dynamics. Thus, we propose a two-stage integrated model that utilizes the benefits of both the macro- and micro-level approaches. In the first stage, potential customers become aware of the innovation, which requires no decision making by the individual. As a result, we employ a macro-level diffusion process to describe the first stage. However, in the second stage potential customers decide whether to adopt the innovation or not, and we utilize a micro-level methodology to model this. We further extend the application to include forward looking behaviour, heterogeneous adopters and segmented Bayesian learning, and utilize the adopter's satisfaction levels to describe biasing and word-of-mouth behaviour. We apply the proposed model to Canadian colour-TV data, and cross-validation results suggest that the new model has excellent predictive capabilities. We also apply the two-stage model to early U.S. hybrid-electric vehicle data and results provide insightful managerial observations.
16

Canadian consumer valuation of farm animal welfare and quality verification the case of pork

Uzea, Adrian Daniel 07 July 2009 (has links)
There is increasing pressure from animal rights organizations (AROs) on restaurant chains, food retailers, and meat processors to implement more stringent farm animal welfare (FAW) requirements for their suppliers. In the United States, AROs have recently initiated successful ballots to phase out confinement practices in several states. In Canada AROs have been pressuring both public and private sector stakeholders to improve FAW. Are FAW issues, however, paramount in the minds of Canadian consumers? Is the demand for more stringent FAW protocols primarily determined by a subset of consumers with very strong preferences or does it signal a more fundamental underlying change in consumer and societal preferences? Given the credence nature of FAW, who do consumers trust (i.e., government vs. private industry vs. independent third parties) in the market place for the provision of FAW quality assurances? What are the determinants of trust in these organizations for providing accurate information about animal welfare?<p> In order to answer these questions, a stated preference consumer survey encompassing FAW issues specific to the Canadian pork sector was tested on two samples of consumers in summer 2008, namely: a general population sample (GPS) across Canada and a sample of AROs members. Consumers participated in a purchase experiment where they had to chose between pork chops characterized by combinations of different levels of FAW attributes (i.e., housing system, gestation stalls, and use of antibiotics), quality verifying organization, and price. Multinomial Logit and Latent Class Logit Models were used to analyse the survey data.<p> Surprisingly, outdoor system does not seem to resonate well with Canadians, as both the GPS and the members of the AROs discounted this attribute. As expected, the AROs members have much stronger preferences for the other FAW attributes than have consumers in the GPS. Nevertheless, significant heterogeneity exists within consumer preferences. Five classes of consumers were identified in the GPS with respect to their preferences for FAW. At one end of the spectrum are the FAW sensitive consumers (12.3%) that have higher willingness-to-pay (WTP) for FAW, while at the other end of the spectrum Price Conscious consumers (18.3%) do not exhibit any WTP for FAW. The other three classes (69.4%) comprise respondents with mixed perceptions regarding FAW. Government and Third Party verification of FAW quality assurances had the strongest influence on consumers preferences in both samples. As well, scientific experts in FAW along with the above two organizations are the most credible in providing information about the welfare of pigs. The extent to which these organizations are knowledgeable about the welfare of pigs is the most important factor enhancing consumers trust. Results from this study suggest that there are potential marketing opportunities for pork chops sourced from pigs raised on farms where sows are kept in groups, and where credible quality assurances can be established, that private industry could consider. As well, the results suggest that consumers would derive benefits from the government taking a more active role with respect to validating FAW quality assurances.
17

The Microfoundations of Housing Market Dynamics

Murphy, Alvin Denis 24 April 2008 (has links)
<p>The goal of this dissertation is to provide a coherent and computationally feasible basis for the analysis of the dynamics of both housing supply and demand from a microeconomics perspective. The dissertation includes two papers which incorporate unique micro data with new methodological approaches to examine housing market dynamics. The first paper models the development decisions of land owners as a dynamic discrete choice problem to recover the primitives of housing supply. The second paper develops a new methodology for dynamically estimating the demand for durable goods, such as housing, when the choice set is large.</p><p>In the first paper, using the new data set discussed above, I develop and estimate the first dynamic microeconometric model of supply. Parcel owners maximize the discounted sum of expected per-period profits by choosing the optimal time and nature of construction. In addition to current profits, the owners of land also take into account their expectations about future returns to development, balancing expected future prices against expected future costs. This forward looking behavior is crucial in explaining observed aggregate patterns of construction. Finally, the outcomes generated by the parcel owners' profit maximizing behavior, in addition to observable sales prices, allow me to identify the parameters of the per-period profit function at a fine level of geography.</p><p>By modeling the optimal behavior of land owners directly, I can capture important aspects of profits that explain both market volatility and geographic differences in construction rates. In particular, the model captures both the role of expectations and of more abstract costs (such as regulation) in determining the timing and volatility of supply in way that would not be possible using aggregate data. The model returns estimates of the various components of profits: prices, variable costs, and the fixed costs of building, which incorporate both physical and regulatory costs.</p><p>Estimates of the model suggest that changes in the value of the right-to-build are the primary cause of house price appreciation, that the demographic characteristics of existing residents are determinants of the cost environment, and that physical and regulatory costs are pro-cyclical. Finally, using estimates of the profit function, I explain the role of dynamics in determining the timing of supply by distinguishing the effects of expected future cost changes from the effects of expected future price changes. A counterfactual simulation suggest that pro-cyclical costs, combined with forward looking behavior, significantly dampen construction volatility. These results sheds light on one of the empirical puzzles of the housing market - what determines the volatility of housing construction?</p><p>In the second paper, I outline a tractable model of neighborhood choice in a dynamic setting along with a computationally straightforward estimation approach. The approach allows the observed and unobserved features of each neighborhood to evolve in a completely flexible way and uses information on neighborhood choice and the timing of moves to recover semi-parametrically: (i) preferences for housing and neighborhood attributes, (ii) preferences for the performance of the house as a financial asset, and (iii) moving costs. In order to accommodate a number of important features of housing market, this approach extends methods developed in the recent literature on the dynamic demand for durable goods in a number of key ways. The model and estimation approach are applicable to the study of a wide set of dynamic phenomena in housing markets and cities. These include, for example, the analysis of the microdynamics of residential segregation and gentrification within metropolitan areas. More generally, the model and estimation approach can be easily extended to study the dynamics of housing and labor markets in a system of cities.</p> / Dissertation
18

Family Formation and Equilibrium Influences

Beauchamp, Andrew W. January 2009 (has links)
<p>This dissertation considers incentives arising from equilibrium influences that affect the sequence of decisions that lead to family formation. The first chapter examines how state regulations directly aimed at abortion providers affect the market for abortion in the United States. Estimates from a dynamic model of competition among abortion providers show that regulations' main impact is on the fixed costs of entry for providers. Simulations indicate that the removal of regulations would promote entry and competition among abortion providers, and because abortions are found to be price sensitive, this would lead to increases in the number of abortions observed. The second chapter tests if an important negative externality of abortion access exists, namely whether abortion access makes prospective fathers more likely to leave pregnant women. Designing a number of empirical tests, I confirm that in some areas where abortion is more accessible women who give birth are more likely to be single mothers, rather than sharing parental responsibility with the biological father. The final chapter, which is joint work with Peter Arcidiacono and Marjorie McElroy, examines how gender ratios influence bargaining power in romantic relationships between men and women. Gender ratios, by influencing the prospects of matching, allow us to estimate preferences for various match characteristics and activities. We find men prefer sexual relationships more than women at high school ages, and that men and women trade off their preferred partner for an increased chance of matching.</p> / Dissertation
19

Essays on Choice and Demand Analysis of Organic and Conventional Milk in the United States

Alviola IV, Pedro A. 2009 December 1900 (has links)
This dissertation has four interrelated studies, namely (1) the characterization of milk purchase choices which included the purchase of organic milk, both organic and conventional milk and conventional milk only; (2) the estimation of a single-equation household demand function for organic and conventional milk; (3) the assessment of binary choice models for organic milk using the Brier Probability score and Yates partition, and (4) the estimation of demand systems that addresses the censoring issue through the use of econometric techniques. In the first paper, the study utilized the estimation of both multinomial logit and probit models in examining a set of causal socio-demographic variables in explaining the purchase of three outcome milk choices namely organic milk, organic and conventional milk and conventional milk only. These crucial variables include income, household size, education level and employment of household head, race, ethnicity and region. Using the 2004 Nielsen Homescan Panel, the second study used the Heckman two-step procedure in calculating the own-price, cross-price, and income elasticities by estimating the demand relationships for both organic and conventional milk. Results indicated that organic and conventional milk are substitutes. Also, an asymmetric pattern existed with regard to the substitution patterns of the respective milk types. Likewise, the third study showed that predictive outcomes from binary choice models associated with organic milk can be enhanced with the use of the Brier score method. In this case, specifications omitting important socio-demographic variables reduced the variability of predicted probabilities and therefore limited its sorting ability. The last study estimated both censored Almost Ideal Demand Systems (AIDS) and Quadratic Almost Ideal Demand System (QUAIDS) specifications in modeling nonalcoholic beverages. In this research, five estimation techniques were used which included the usage of Iterated Seemingly Unrelated Regression (ITSUR), two stage methods such as the Heien and Wessells (1990) and the Shonkwiler and Yen (1999) approaches, Generalized Maximum Entropy and the Dong, Gould and Kaiser (2004a) methods. The findings of the study showed that at various censoring techniques, price elasticity estimates were observed to have greater variability in highly censored nonalcoholic beverage items such as tea, coffee and bottled water.
20

Parents' Preferences for Drug Treatments in Juvenile Idiopathic Arthritis: A Discrete Choice Experiment

Burnett, Heather 05 December 2011 (has links)
BACKGROUND: Parents of children with juvenile idiopathic arthritis (JIA) are often forced to make trade-offs between the effectiveness, convenience, safety, and cost of drug treatments for their child. METHODS: A discrete choice experiment was administered to parents of children with JIA to determine their preferences for drug treatments. Multinomial logit regression was used to estimate part-worth utilities and willingness-to-pay. RESULTS: Participation in daily activities was the most important attribute, followed by child reported pain. Child age, gender, years with JIA, and household income had the greatest impact on preferences. Parents’ were willing to pay $2,080 to switch from a drug representing methotrexate to etanercept (95% CI $698, $4,065). CONCLUSIONS: Parents of children with JIA have the highest maximum willingness-to-pay for drug treatments that improve daily functioning and reduce pain. Cost is a significant factor in the decisions that parents make surrounding the best treatment for a child.

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