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Analysis of Whole Milk vs. Low-Fat Milk Consumption Among WIC Children Before Programmatic ChangesBayar, Emine 2011 May 1900 (has links)
The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is one of the food assistance programs targeted at low-income women, infants and children up to age five by providing foods, nutrition education and other services. Recent updates in food packages provided by WIC include the addition of fruits, vegetables and whole wheat products as well as the removal of whole milk for women and children two years and older. This thesis concentrates on preschool children participants in the WIC program and their milk consumption habits prior to programmatic changes. Analyzing diet preferences of these children is crucial since a quarter of the population of children aged one thorough five participates in the WIC program; as well, they are not eligible to receive whole milk with WIC food packages after the implementation of revisions.
The objective is to describe the profile of preschool WIC children and their milk consumption attributes based on the National Food and Nutrition (NATFAN) questionnaire designed and conducted by the Institute for Obesity Research and Program Evaluation at Texas A & M University before the release of the revised WIC food packages. Additionally, findings of the study are compared with the National Health and Nutrition Examination Survey (NHANES) 2005-2006 dataset results. Milk consumption preferences of WIC children are analyzed nationwide and impacts of race, ethnicity, regional, and other demographic characteristics are observed. Using both NATFAN and NHANES datasets provides a comparison of actual and self-reported participation outcomes.
Discrete choice models were used in this analysis, in particular binary logit and multinomial logit models. The results of the thesis indicate that WIC preschool children mostly drink whole milk (36.17 percent) and 2 percent fat milk (49.94 percent). Two year old participants, children located in the South and participants whose caregivers are younger and less educated are more likely to consume whole milk. Caucasian children are less likely to choose whole milk and more likely to choose reduced fat milk; African Americans are more likely to select whole milk. Furthermore, diet preferences and knowledge of parents/caregivers play a major role on milk consumption of children. Children whose caregivers are willing to give low-fat milk to children aged two to five are less likely to drink whole milk.
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Diagnostics in some Discrete Choice ModelsNagel, Herbert, Hatzinger, Reinhold January 1990 (has links) (PDF)
Discrete choice models form a class of models widely used in econometrics for modelling the individual choice from a finite set of alternatives. The most widely used model is the multinomial logit model, implicitly assuming independence of irrelevant alternatives. A generalization is the nested multinomial logit model, relaxing this strong assurnp tion. Viewing both models as nonlinear regression models a set of diagnostics is derived. This includes a hat matrix, measures of leverage, influence and residuals and an approximation to the parameters for case deletion. In an example for the multinomid logit model a good performance of these diagnostics is observed and the parameter approximation by the proposed formula is better than a one step Newton-Raphson procedure. In an example for the nested logit model a constructed outlier with high influence is revealed by the measures of leverage and residual, but the parameter approximation is insufficient. (author's abstract) / Series: Forschungsberichte / Institut für Statistik
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Cross-Border Contagion in the Banking Sector: The Case of Nordic CountriesBaronaite, Lina January 2014 (has links)
"Cross-Border Contagion in the Banking Sector: The Case of Nordic Countries" by Lina Baronaite Abstract: The objective of the thesis is to estimate the degree of cross-border contagion among the Nordic banking sectors. It analyzes a sample of sixteen largest listed Nordic banks from January 2004 to January 2014. Using a multinomial logit model we test whether there is any degree of contagion among the four banking sectors, whether it is more pro- nounced for larger banks and whether the recent financial crisis has exacerbated it. Our results are in line with similar studies conducted for other countries. In particular, we find that a shock in one bank- ing sector is positively associated with an increase in shocks in another banking sector. Second, these shocks are larger and more significant for larger and more active international banks. Finally, the effect of the recent financial crisis has ambiguous effects on the cross-sectoral banking contagion. It appears that contagious links between some sec- tors weakened (Sweden and Denmark, Sweden and Finland). Other economies (Sweden and Norway) on the contrary became more depen- dent on each other. The results are robust to a wide variety of changes in specifications.
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The Choice of STIGA Table Tennis Blades : Evidence from ChinaZHANG, LEI, YOU, XI January 2010 (has links)
The purpose of this paper is to investigate how individuals with different characteristics make their choice-decisions when consuming STIGA table tennis blades, which are combinations of various attributes, such as price, control, attack, etc. It is expected that the general trend of choice behavior on this special commodity can be, at least to some extent, revealed. Data were collected using questionnaires sent to registered members of a table tennis club in China. The questionnaires included information and questions about individuals’ monthly income levels, ages, technique styles, etc. A multinomial logit model was then applied to analyze factors determining Chinese consumers’ choice behavior on STIGA table tennis blades. The results indicated that the main element influencing Chinese consumers’ choice of STIGA ping-pong blades was the technique style and other variables did not seem to influence the choice of table tennis blades. These results might be explained by the limited sample size as well as unmeasured and immeasurable factors. Thus, a more extensive research is needed to be conducted in the future.
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The Effect of Welfare Reform on Childbirth, Marriage, and DivorcePakdeethai, Pimrak 2009 August 1900 (has links)
This dissertation contains two essays on the effect of welfare reform on child-
birth, marriage, and divorce. In the first essay, I exploit the cross state variation in
welfare reform implementation to identify its effect on birth rates. The results from
multinomial logit models suggest that the welfare reform significantly increased the
probability of marital births. The out-of-wedlock birth rates decreased but this effect
is not significant. The strong work incentives decrease birth rates in both marital
and non-marital statuses suggesting that bearing a child is not appealing for women
who are more progressive in careers. However, the most aggressive welfare policy
significantly increases marital birth as expected. Birth rates among teenage girls are
not affected by the welfare reform. I further investigate the effect of the family cap
policy. Using a semi-natural experiment, I compare the birth rate of women who
already have had a second or higher order birth (treatment group) to women who
have had one child (comparison group), in states with and without family caps. The
difference in difference estimates reveal a strictly negative effect of family caps on the
higher order birth rates as expected.
In the second essay, I use reduced-form estimation and cross-state variation in
timing of reform adoption to extract both mechanical and behavioral effects of welfare
reform on marriage and divorce likelihood. I construct a flow measure of marriage and
divorce by matching individuals in the Current Population Survey from March 1988B
to 2002 and observing changes in marital status. I introduce a converse matching procedure to detect women who are not in the survey for two consecutive years. I
find that the welfare reform has a significantly negative effect on marriage rates and
an insignificant effect on divorce rates. The Difference-in-Difference estimates suggest that marriage among disadvantaged women is negatively affected by the welfare
reform. I also provide a theoretical model to decompose the effect of welfare reform
on marriage due to each of the components of the reform, i.e., time limits, work sanctions, earnings disregards, and maximum cash benefits. My results provide a novel
explanation for the effects of work incentives and welfare restrictions on marriage.
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Examining solid waste management issues in the City of BryanArekere, Dhananjaya Marigowda 12 April 2006 (has links)
Economic aspects of household recycling behavior and attitudes in City of Bryan are examined to improve solid waste management policies in the city. Using survey data collected by mail and personal interviews, residents attitudes towards solid waste management are analyzed, in general, and specifically, the factors influencing recycling behavior examined using logistic regression. In addition, three alternative policies are presented to respondents. First, support for an additional drop-off recycling center (Policy I) is examined. Second, WTP for two different recycling programs, curbside recycling service (Policy II), and curbside recycling with a drop-off recycling center (Policy III), as a function of socio-economic factors thought to influence WTP are computed using contingent valuation method, an indirect valuation tool. Finally, preference for a particular policy among the three alternatives presented to the residents of Bryan is explored. Because of the different data collection modes and assumptions on the bid prices two logit models are estimated to examine recycling behavior, and Policy I and two multinomial logit models for the most preferred policy, whereas four logit models are estimated for Policy II and III.
The estimated models are similar both within the Policies and between the Policies in terms of the affects of variables, significance of coefficients, and consistency with previous studies indicating a potential set of factors that can be used to explain WTP for recycling services. Bryan residents that are female, white, employed, have higher incomes, have children, own a house, and are self-perceived environmentalists tend to recycle more. Similarly, males, nonwhites, older respondents, students, non-environmentalists and non-recyclers are more likely to support an additional drop-off center. WTP for Policy II is positively influenced by males, whites, respondents who are employed, low-income respondents, environmentalists, non-recyclers, and those who support Policy I. In comparison, WTP for Policy III is positively influenced by females, whites, respondents who are employed, younger respondents, environmentalists, non-recyclers, and those who support Policy I. In the case of both Policies I and II, the bid price negatively influences WTP as expected. While the WTP for Policy II is slightly higher than the estimated cost of a curbside recycling service ($2.50), the WTP for Policy III is lower than the estimated cost. No consistent pattern emerges across most of the coefficients and the four possible alternatives, three proposed policies and the current situation. However, probabilities computed using the multinomial logit results is the highest for Policy II, followed by either Policy III or no change to the existing solid waste management policy.
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Study of Efficiency, Output Loss and Soil Erosion in Fiji's Ginger IndustryWaisiki Naqarase Gonemaituba Unknown Date (has links)
The ginger industry is one of the key industries identified by the Fiji government in its diversification strategy to accommodate the remnants of the withdrawal of the European Union’s sugar preferences. There is considerable pressure on small industries such as ginger in search of ways in which they can be made to operate efficiently and sustain the economy. Expansion of commercial agriculture into marginal land which is unsustainable adds enormous pressure on land causing soil erosion. Coupled with this is the quality issue which is a serious problem of ginger production and has reduced its competitiveness over the years. This study focuses on two types of losses in ginger production to provide an integrated approach to policy making and computing production losses. One is the observable output loss at the farm site that is not sold due to sub-standard quality related to disease and the other is the unobserved output loss due to inefficient production. The research attempts to answer the question of whether the Fiji ginger farmers are producing efficiently, and at what levels. The relative importance of each input in ginger production is examined. The study undertakes to determine the effects of key variables on farm efficiency. Also examined is the overall farm profiles based on the efficiency rankings of the ginger producers. Furthermore, this research attempts to determine factors that influence soil erosion, and those that influence the observed ginger loss. Using cross-sectional data from a ginger farm survey conducted in June 2007, this research estimates a stochastic production frontier which incorporates soil erosion as an input in the framework. Very few studies have looked at the impact of soil erosion in this context; hence, this study fills the gap by incorporating land quality in the analysis. Farms were found to produce at 69% of their maximum potential output and soil erosion resulted in 6.8% loss in ginger output. This also implies that using the same resources, technology and farming techniques efficiently can lead to a 31% increase in output. While unobserved loss to farm income is a 27% (F$4.6m) increase over the observable loss at farm site, the revenue loss to the whole industry is at least 30% (F$5.07m). Profit was a key determinant of both losses, but staying on farm, slope of land, manure use and hot water treatment affected the observed but not unobserved loss. Although farmer education had no effect on both losses, it was important for undertaking soil conservation. Fiji is in a good position to increase production as education, age and experience of farmers were not significant determinants of efficiency. Thus, displaced farmers from sugar cane farming (given serious concerns of the viability of that industry) can be encouraged to move with ease into ginger as an alternative livelihood. Lastly, the study highlights some practical implication which calls for an integrated package of policies related to use of best farming techniques, land tenure and, agricultural extension and support services for sustainable agricultural growth.
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Probabilidade de acesso e gastos com medicamentos no Brasil: estudos a partir de dados da PNAD e da POFda Silva Vasconcelos, Rafael 31 January 2011 (has links)
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Previous issue date: 2011 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Essa dissertação é dividida em dois ensaios. O primeiro objetiva caracterizar a
demanda por medicamentos no Brasil. Para isso é feita uma revisão da literatura sobre
o tema e expostas suas particularidades para o caso brasileiro por meio dos microdados
da POF 2002-2003. Com isso são estimadas as probabilidades de gastos por categoria
de medicamento. Conforme os resultados, em geral, essas probabilidades são crescentes
com a renda e o grau de instrução do chefe da família. Contudo, outras características
como raça, região e idade possuem relevantes efeitos sobre essas probabilidades, onde isso
dependerá também do medicamento adquirido. O segundo ensaio visa apresentar como se dá
o acesso aos medicamentos pelos brasileiros. Para tanto são aplicados modelos de Escolha
discreta, para em seguida, com os dados da PNAD-Saúde 2009, a partir de estimações por
Multinomial Logit e Nested Logit, realizar inferências sobre a tomada de decisão de consumo
dos indivíduos. Os resultados sugerem que a renda, o grau de instrução e o tipo de doenças
infringidas são fatores relevantes. Onde a presença deste último fator afeta diretamente a
tomada de decisão de consumo dos brasileiros, principalmente, no caso das doenças mais
danosas à saúde
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Estimating irrigation water demand with a multinomial logit selectivity modelHendricks, Nathan January 1900 (has links)
Master of Science / Department of Agricultural Economics / Jeffrey M. Peterson / Understanding irrigation water demand is vital to policy decisions concerning water scarcity. This thesis evaluates irrigation water-use responses to changes in prices, while accounting for cross-sectional characteristics of irrigators’ resource settings. An irrigator’s profit-maximizing decision is modeled in two stages. In the first stage, he decides which crop to plant, and in the second stage he decides how much water to apply given the crop choice.
This thesis employs an econometric modeling technique not previously used in the irrigation water demand literature, a multinomial logit selectivity model. This econometric technique allows the intensive (change in water use for each crop in the short run) and extensive (change in water use in the long run due to changes in crop-choice) margin effects to be computed in a simultaneous equation system. A multinomial logit selectivity model has applications to many resource issues in production agriculture where the two-stage decision process is common. The model is estimated from field-level data on water use and crop-choice for a 25-county region in western Kansas over the period 1991-2004.
Water use was found to be highly inelastic to the price of natural gas, but becomes more elastic as the price increases. The intensive margin effect was significant for natural gas price. The extensive margin effect only comprised half the total effect under high natural gas prices and was negligible for low prices. However, the extensive margin effect under high natural gas prices declined over time due to more efficient irrigation systems and improved crop varieties. The intensive margin effect explained most of the water use response from changes in other variables, including corn price. An increase in corn price has a negligible extensive margin effect because corn is most often substituted with alfalfa, which has a similar water requirement.
Inelastic demand implies that policies aiming to conserve the Ogallala Aquifer by increasing the price of water will not accomplish their purpose and will affect irrigators’ incomes. More effective policies would be voluntary or mandatory quantity restrictions. However, efficient restrictions would need to account for spatial variation in the rate of depletion and the remaining saturated thickness.
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El efecto de la retroalimentación de los consumidores sobre la planificación del surtidoCarrasco Heine, Óscar Felipe January 2017 (has links)
Magíster en Gestión de Operaciones. Ingeniero Civil Industrial / Los principales antecedentes y la motivación del presente trabajo provienen de la teoría de
Assortment, los modelos de elección discreta y los procesos de Social Learning. Se apunta a
reunir parte de la vasta literatura en torno a estos temas, proponiendo un modelo matemático
que incorpore el feedback de los consumidores en la elección del surtido de productos a ofrecer
por parte de un vendedor.
El modelo propuesto incluye un comerciante minorista quien se enfrenta a una secuencia
finita de clientes, los que tienen la opción de escoger alguno de los productos ofrecidos por el
vendedor. En caso de comprar alguno, descubren su calidad y la reportan de manera pública,
siendo esta información utilizada por futuros consumidores en su proceso de decisión mediante
actualización bayesiana de sus creencias. Estos reportes a la vez permiten al retailer - quien
sólo puede ofrecer una cantidad limitada de productos - optimizar su oferta, escogiendo aquel
conjunto de alternativas que le entregue un mayor beneficio esperado.
La manera natural para abordar el problema de optimización de assortment enfrentado
por el vendedor es mediante Programación Dinámica Estocástica, al tratarse de una situación
en tiempo discreto donde período a período se debe tomar una decisión ante un determinado
estado del sistema. Sin embargo, el número de estados posibles aumenta explosivamente en
función de los parámetros considerados, volviéndose un problema virtualmente imposible de
resolver en instancias realistas. Es por ello que se opta por Programación Dinámica Aproximada,
proponiéndose 3 heurísticas que permiten obtener resultados en contextos en los cuales
no es posible optimizar de manera exacta.
A modo de referencia, se compara el rendimiento de las heurísticas con el de una estrategia
bajo la cual el vendedor no considera las evaluaciones hechas por los clientes, ni la incidencia
de sus decisiones en períodos futuros. La diferencia en los beneficios llega a ser enorme,
observándose en los experimentos realizados aumentos superiores a 300% al utilizar alguno
de los algoritmos sugeridos, en vez de obviar la información disponible. Esto no solo valida
la calidad de los métodos heurísticos propuestos, sino que sobre todo ilustra la importancia
de considerar el feedback de los consumidores. / Este trabajo ha sido parcialmente financiado por CONICYT
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