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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.
71

Advances in land-use and stated-choice modeling using neural networks and discrete-choice models

Ramsey, Steven M. January 1900 (has links)
Doctor of Philosophy / Department of Agricultural Economics / Jason S. Bergtold / Jessica L. Heier Stamm / Applied research in agricultural economics often involves a discrete process. Most commonly, these applications entail a conceptual framework, such as random utility, that describes a discrete-variable data-generating process. Assumptions in the conceptual framework then imply a particular empirical model. Common approaches include the binary logit and probit models and the multinomial logit when more than two outcomes are possible. Conceptual frameworks based on a discrete choice process have also been used even when the dependent variable of interest is continuous. In any case, the standard models may not be well suited to the problem at hand, as a result of either the assumptions they require or the assumptions they impose. The general theme of this dissertation is to adopt seldom-used empirical models to standard research areas in the field through applied studies. A common motivation in each paper is to lessen the exposure to specification concerns associated with more traditional models. The first paper is an attempt to provide insights into what --- if any --- weather patterns farmers respond to with respect to cropping decisions. The study region is a subset of 11 north-central Kansas counties. Empirically, this study adopts a dynamic multinomial logit with random effects approach, which may be the first use of this model with respect to farmer land-use decisions. Results suggest that field-level land-use decisions are significantly influenced by past weather, at least up to ten years. Results also suggest, however, that that short-term deviations from the longer trend can also influence land-use decisions. The second paper proposes multiple-output artificial neural networks (ANNs) as an alternative to more traditional approaches to estimating a system of acreage-share equations. To assess their viability as an alternative to traditional estimation, ANN results are compared to a linear-in-explanatory variables and parameters heteroskedastic and time-wise autoregressive seemingly unrelated regression model. Specifically, the two approaches are compared with respect to model fit and acre elasticities. Results suggest that the ANN is a viable alternative to a simple traditional model that is misspecified, as it produced plausible acre-response elasticities and outperformed the traditional model in terms of model fit. The third paper proposes ANNs as an alternative to the traditional logit model for contingent valuation analysis. With the correct network specifications, ANNs can be viewed as a traditional logistic regression where the index function has been replaced by a flexible functional form. The paper presents methods for obtaining marginal effect and willingness-to-pay (WTP) measures from ANNs, which has not been provided by the existing literature. To assess the viability of this approach, it is compared with the traditional logit and probit models as well an additional semi-nonparametric estimator with respect to model fit, marginal effects, and WTP estimates. Results suggest ANNs are viable alternative and may be preferable if misspecification of the index function is a concern.
72

The Effect of Thought Detection on Anxiety Responses

Komechak, Marilyn Gilbert 05 1900 (has links)
The problem of this study was to analyze the effects of contingent reinforcement on the presence of thoughts defined as anxiety responses. The two types of data, observed and introceptive, were used to determine the effects of reinforcement. The observed data from the peripheral physiological pre- and post-measures included heart rate, blood pressure, and the Taylor Manifest Anxiety Scale data. The introceptive data supplied by subjects were the daily percentages of anxious thought detections subsequent to a baseline period. The daily percentages were formed by the subject's monitoring his own thoughts, with the monitoring prompted by an automatic tone device which emitted a tone approximately every four minutes. The daily percentage of anxious thoughts was formed by dividing the number of tones the subject heard into the number of anxious thoughts occurring at the time of the tone.The problem of this study was to analyze the effects of contingent reinforcement on the presence of thoughts defined as anxiety responses. The two types of data, observed and introceptive, were used to determine the effects of reinforcement. The observed data from the peripheral physiological pre- and post-measures included heart rate, blood pressure, and the Taylor Manifest Anxiety Scale data. The introceptive data supplied by subjects were the daily percentages of anxious thought detections subsequent to a baseline period. The daily percentages were formed by the subject's monitoring his own thoughts, with the monitoring prompted by an automatic tone device which emitted a tone approximately every four minutes. The daily percentage of anxious thoughts was formed by dividing the number of tones the subject heard into the number of anxious thoughts occurring at the time of the tone. The main findings in this study were 1. Although not statistically significant, the experimental subjects were found to demonstrate consistently lower mean heart rate and blood pressure following the experimental period. The control subjects' scores were nonsignificantly greater for heart rate and blood pressure at the conclusion of the study. 2. The results further suggested that contingent reinforcement alone did not produce the significant shifts found in the thought frequency of individual subjects. It is likely that both reinforcement and thought monitoring had
73

Ekonomisk värdering av investeringar på Gültzauudden : Påverkar hälsan betalningsviljan? / Economic valuation of investments on Gültzauudden : Does health affect the willingness to pay?

Persson, Sarah January 2021 (has links)
I samband med den pågående urbaniseringen är det viktigt att vi tar hand om och bevarar de grönområden som finns i våra städer. Genom denna studie undersöks boende i Luleå kommuns betalningsvilja för förändringar i form av en investering på Gültzauudden. Bakomliggande faktorer till individens betalningsvilja undersöks, där individens hälsa för första gången inkluderas. En enkät, som inspirerats av metoden contingent valuation, har skickats ut via Facebook och till två företag i Luleå. Studien undersöker endast vuxna i Luleå kommuns betalningsvilja för ett specifikt grönområde. Med hjälp av 218 observationer fastställdes den individuella genomsnittliga betalningsviljan till 134 SEK. Det totala ekonomiska värdet av förbättringar på Gültzauudden i form av en investering uppgår till cirka åtta miljoner kronor. Faktorer som påverkar individens betalningsvilja är om individen besöker området för en kulturaktivitet, kön och hälsotillstånd. Investeringar som kan satsas på är fler grillplatser, anordning av kulturevenemang och utomhusgym.
74

Contingent Valuation of Early Intervention Programs for Handicapped Children

Escobar, Colette M. 01 May 1986 (has links)
Early intervention programs for handicapped preschool children may have long-term implications for the children and their families. Economic eva luations of these programs have been conducted to measure costs and bene fit s, but parental wi l lingness-to-pay has been overlooked in these analyses. Parental willingness-to-pay, as a measure of consumer surplus, could complete the measure of benefits and provide both policymakers and practitioners with useful information for decisionmaking. In this study, the impli cations of eliciting willingness-to-pay responses for an early intervention program for handicapped preschoolers are discussed. A survey technique, known as the contingent valuation method (CVM) , is applied to program to empirically estimate wil lin gness-to-pay for the total program and for particular components of the program. Also investigated are the implications of using a rationality test in the survey to determine if consumer responses are in accordance with assumptions for rational consumer behavior. Results indicate relatively high willingness-to-pay for the program as whole, but low value is associated with program components. This implies that parents may value these programs more for the respite rather than specialized services offered. Results of the rationality test support the hypothesis that such a measure is necessary in survey designs of this nature.
75

Negative Reinforcement Through Contingent Easy-Task Presentation

Nickerson, Cicely Irene 01 May 2015 (has links)
Escape from instructional demands is one of the most common functions of problem behavior. Some research suggests that a switch from difficult to easy tasks may function as a reinforcer for problem behavior. This is of particular concern for situations in which easy tasks are part of the intervention procedure to reduce problem behavior. This project examined the reinforcing effects of a switch from low-probability (low-p) to high-probability (high-p) tasks for individuals whose problem behavior was maintained by escape from demands. It also provided preliminary evidence as to the quality of reinforcement provided by a switch from low- high-p tasks. Three individuals with disabilities who were referred for treatment of escape-maintained problem behavior participated in this research. We used a multi-element design to compare the effects of two intervention conditions on problem behavior and compliance in relation to control and baseline conditions. During the control condition, no demands were presented, and the participant had continuous access to preferred items and attention. In the baseline condition (break), a break from low-p demands was presented contingent on problem behavior. In the first intervention condition, problem behavior no longer resulted in a break from demands (escape extinction). During the second intervention condition, problem behavior following low-p tasks resulted in a switch to high-p tasks. All participants engaged in elevated levels of problem behavior and decreased compliance when problem behavior resulted in a switch of tasks. These results imply that for individuals whose problem behavior is maintained by escape from demands, a switch from low- to high-p tasks may reinforce problem behavior.
76

EXAMINING EFFECTIVE TEACHER PRACTICES IN HIGHER EDUCATION

Paoletta, Toni Marie 09 May 2020 (has links)
No description available.
77

Examining preferences for prevention of Louisiana's wetland loss

Moore, Ross Gordon 01 May 2010 (has links)
This study analyzed preferences for wetland-loss prevention in coastal Louisiana. Data were obtained through a contingent-valuation mail survey of a random sample of Louisiana households. Results, based on 511 responses, indicate that respondents have a strong preference for a short-run program (72.41% chose this program over a long-run program or no action). Respondents that had higher incomes, were white, had prior knowledge of ongoing restoration efforts, and had confidence in government were more likely to support some program relative to no action, as were those citing hurricane, environmental, and/or climate-change protection as their primary concern. Older respondents and those with negative perceptions of climate change were more likely to prefer the short-run over the long-run program. Median net present value of willingness to pay (assuming 18.37% discount rate) was estimated at $17,491 per household for the multinomial logit model and $3,307 under the Turnbull lower-bound method.
78

User benefits of urban agriculture in Havana, Cuba : an application of the contingent valuation method

Henn, Patrick. January 2000 (has links)
No description available.
79

The Fractured Faculty: Contingent Academic Labor and the Transformation of American Higher Education

Klainot-Hess, Elizabeth Ann 30 December 2020 (has links)
No description available.
80

Carbon Sequestration on Nonindustrial Private Forest Lands for Climate Change Mitigation in the Southern United States

Khanal, Puskar Nath 11 December 2015 (has links)
To effectively implement climate change mitigation and carbon sequestration activities in the southern US, nonindustrial private forest (NIPF) landowner participation is necessary because of the significant number of acres of forest land under their ownership. This study intended to develop a typology of NIPF landowners based on their reasons of owning forestland, assess their attitude toward climate change and carbon sequestration, and evaluate their participation behavior toward forest carbon sequestration in the southern US. A mail survey of NIPF landowners in the southern US was used to collect the data necessary for this study. Study results indicated that landowners in the southern US could be segmented into multi-objective, timber and amenity oriented landowners; and landowner groups differed in terms of their ownership characteristics, management behavior, and interest toward forest carbon sequestration. Additionally, the southern landowner attitudes toward climate change and carbon sequestration could be grouped into positive, negative, and undecided types; with the undecided group composing the largest proportion of landowners. However, few landowners indicated having a good understanding of forest carbon sequestration, indicating the need for more education and outreach activities in this region. In addition, landowner willingness to participate in carbon sequestration practices was different when such practices were more profitable, revenue neutral or less profitable than timber management only. Although many landowners would require a significant profit to participate in carbon sequestration programs, others would participate with little or no incentives. Those having recreational goals for their property were the most likely landowners to participate in carbon sequestration. Similarly, positive attitudes toward climate change (i.e., with a belief that climate change is scientifically proven) and a good understanding of forest carbon sequestration positively affected landowner participation in forest carbon sequestration. Economic implementation of climate change policy could be achieved by designing education, incentives, or assistance programs to connect with recreational goal landowners in the southern US.

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