970 resultados para multinomial logit model
Resumo:
The Government of Bangladesh is planning to develop and implement Bus Rapid Transit (BRT) in Dhaka city. This paper presents a stated choice survey conducted to understand workers’ attitudes toward BRT in Dhaka. The survey data are analysed using a multinomial logit (MNL) model to scrutinize social and economic factors’ impact on participant’s mode choices. Analysis results reveal that males, and workers with higher age, education qualification, and income have greater tendency towards choosing BRT.
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This study investigates: –how travel and socio-demographic attributes act on workers’ mode choice decisions in Dhaka –whether Dhaka’s commuters would choose BRT for their work trip once implemented •Very limited research exists on users’ perceptions of BRT in developing countries’ megacities •We adopted a discrete choice modelling approach •As BRT has not yet been implemented in Dhaka, we collected Stated Choice (SC) survey data including a hypothetical BRT mode to understand factors important to workers’ mode choice decisions •We compare the impact of travel factors between Dhaka and cities of developed countries
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This research has made substantial and novel contributions to the body of knowledge by combining mixed, quantitative and qualitative analyses to understand the potential uptake of a proposed Bus Rapid Transit (BRT) system by commuters in a developing country's megacity, using Dhaka, Bangladesh as the case study. The quantitative analysis took a unique approach by dividing the analysis into an exploratory analysis of Revealed Preference (RP) survey data, modelling with RP data and modelling with Preferred Mode Selection (PMS) survey data. The qualitative analysis also made a novel contribution by taking a "lesson drawing" approach from model cities in analysing Dhaka's transport environment.
Resumo:
The Government of Bangladesh is planning to develop and implement Bus Rapid Transit (BRT) in Dhaka city. This paper presents a stated choice survey conducted to understand workers’ attitudes toward BRT in Dhaka. The survey data are analysed using a multinomial logit (MNL) model to scrutinize social and economic factors’ impact on participant’s mode choices. Analysis results reveal that males, workers of higher age, education qualification, and income have a greater tendency towards choosing BRT.
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A Violência entre Parceiros Íntimos (VPI) tem sido reconhecida como um importante problema de saúde pública e um fator de risco para agravos a saúde de mulheres e crianças. Os serviços de saúde desempenham importante papel na detecção precoce da VPI, especialmente em momentos da vida nos quais se preconiza o atendimento sistematizado, como na gestação e primeira infância. Esta dissertação tem como objetivo principal estimar a probabilidade de ocorrência de Violência Física entre Parceiros Íntimos (VFPI) durante a gestação e/ou pós-parto em população atendida em Unidades Básicas de Saúde (UBS), segundo diferentes características sócio-econômicas e demográficas da clientela. Trata-se de um estudo transversal, realizado com usuárias de 5 UBS da cidade do Rio de Janeiro no ano de 2007. Foram entrevistadas 811 mães de crianças de até cinco meses de idade, que não possuíam nenhuma contra-indicação formal para a amamentação e que relataram ter tido pelo menos uma relação amorosa um mês ou mais durante a gestação ou no período do pós-parto. Condições socioeconômicas e demográficas e relativas aos hábitos de vida do casal foram consideradas como potenciais preditores de violência. Utilizou-se a versão em português da CTS2 para identificar as situações de VPI. A variável de desfecho foi analisada em três níveis: ausência de VFPI, presença de VFPI no período da gestação ou do pós-parto e presença de VFPI em ambos os períodos. Utilizou-se um modelo logito-multinomial para as projeções de prevalências segundo os descritores selecionados. Os fatores que mais aumentaram a probabilidade de ocorrência de violência durante a gestação e/ou nos primeiros cinco meses de vida da criança foram: idade materna < 20 anos, escolaridade materna inferior ao 2 grau completo, ter 2 ou mais filhos menores de cinco anos, tabagismo materno, uso inadequado de álcool pela mãe e/ou companheiro, uso de drogas pela mãe e/ou companheiro e percepção materna sobre a saúde do bebê aquém da esperada. Entre mães com todas estas características, a estimativa de prevalência projetada de VFPI na gestação e/ou no pós-parto chegou a 96,4%, sendo 59,4% a estimativa de ocorrência em apenas um dos dois períodos e 37% em ambos. Por outro lado, a probabilidade de ocorrência de VFPI cai a 3,6% em famílias sem estas características. Os resultados indicam que a presença de certas características da criança e de sua família aumenta enormemente a probabilidade de ocorrência de VFPI, devendo ser levadas em consideração ao se estabelecer estratégias de intervenção que visem à detecção precoce e uma efetiva intervenção.
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We estimate a carbon mitigation cost curve for the U.S. commercial sector based on econometric estimation of the responsiveness of fuel demand and equipment choices to energy price changes. The model econometrically estimates fuel demand conditional on fuel choice, which is characterized by a multinomial logit model. Separate estimation of end uses (e.g., heating, cooking) using the U.S. Commercial Buildings Energy Consumption Survey allows for exceptionally detailed estimation of price responsiveness disaggregated by end use and fuel type. We then construct aggregate long-run elasticities, by fuel type, through a series of simulations; own-price elasticities range from -0.9 for district heat services to -2.9 for fuel oil. The simulations form the basis of a marginal cost curve for carbon mitigation, which suggests that a price of $20 per ton of carbon would result in an 8% reduction in commercial carbon emissions, and a price of $100 per ton would result in a 28% reduction. © 2008 Elsevier B.V. All rights reserved.
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Scepticism over stated preference surveys conducted online revolves around the concerns over “professional respondents” who might rush through the questionnaire without sufficiently considering the information provided. To gain insight on the validity of this phenomenon and test the effect of response time on choice randomness, this study makes use of a recently conducted choice experiment survey on ecological and amenity effects of an offshore windfarm in the UK. The positive relationship between self-rated and inferred attribute attendance and response time is taken as evidence for a link between response time and cognitive effort. Subsequently, the generalised multinomial logit model is employed to test the effect of response time on scale, which indicates the weight of the deterministic relative to the error component in the random utility model. Results show that longer response time increases scale, i.e. decreases choice randomness. This positive scale effect of response time is further found to be non-linear and wear off at some point beyond which extreme response time decreases scale. While response time does not systematically affect welfare estimates, higher response time increases the precision of such estimates. These effects persist when self-reported choice certainty is controlled for. Implications of the results for online stated preference surveys and further research are discussed.
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This paper compares the Random Regret Minimization and the Random Utility Maximization models for determining recreational choice. The Random Regret approach is based on the idea that, when choosing, individuals aim to minimize their regret – regret being defined as what one experiences when a non-chosen alternative in a choice set performs better than a chosen one in relation to one or more attributes. The Random Regret paradigm, recently developed in transport economics, presents a tractable, regret-based alternative to the dominant choice paradigm based on Random Utility. Using data from a travel cost study exploring factors that influence kayakers’ site-choice decisions in the Republic of Ireland, we estimate both the traditional Random Utility multinomial logit model (RU-MNL) and the Random Regret multinomial logit model (RR-MNL) to gain more insights into site choice decisions. We further explore whether choices are driven by a utility maximization or a regret minimization paradigm by running a binary logit model to examine the likelihood of the two decision choice paradigms using site visits and respondents characteristics as explanatory variables. In addition to being one of the first studies to apply the RR-MNL to an environmental good, this paper also represents the first application of the RR-MNL to compute the Logsum to test and strengthen conclusions on welfare impacts of potential alternative policy scenarios.
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L'objectif principal de ce travail est d’étudier en profondeur certaines techniques biostatistiques avancées en recherche évaluative en chirurgie cardiaque adulte. Les études ont été conçues pour intégrer les concepts d'analyse de survie, analyse de régression avec “propensity score”, et analyse de coûts. Le premier manuscrit évalue la survie après la réparation chirurgicale de la dissection aigüe de l’aorte ascendante. Les analyses statistiques utilisées comprennent : analyses de survie avec régression paramétrique des phases de risque et d'autres méthodes paramétriques (exponentielle, Weibull), semi-paramétriques (Cox) ou non-paramétriques (Kaplan-Meier) ; survie comparée à une cohorte appariée pour l’âge, le sexe et la race utilisant des tables de statistiques de survie gouvernementales ; modèles de régression avec “bootstrapping” et “multinomial logit model”. L'étude a démontrée que la survie s'est améliorée sur 25 ans en lien avec des changements dans les techniques chirurgicales et d’imagerie diagnostique. Le second manuscrit est axé sur les résultats des pontages coronariens isolés chez des patients ayant des antécédents d'intervention coronarienne percutanée. Les analyses statistiques utilisées comprennent : modèles de régression avec “propensity score” ; algorithme complexe d'appariement (1:3) ; analyses statistiques appropriées pour les groupes appariés (différences standardisées, “generalized estimating equations”, modèle de Cox stratifié). L'étude a démontrée que l’intervention coronarienne percutanée subie 14 jours ou plus avant la chirurgie de pontages coronariens n'est pas associée à des résultats négatifs à court ou long terme. Le troisième manuscrit évalue les conséquences financières et les changements démographiques survenant pour un centre hospitalier universitaire suite à la mise en place d'un programme de chirurgie cardiaque satellite. Les analyses statistiques utilisées comprennent : modèles de régression multivariée “two-way” ANOVA (logistique, linéaire ou ordinale) ; “propensity score” ; analyses de coûts avec modèles paramétriques Log-Normal. Des modèles d’analyse de « survie » ont également été explorés, utilisant les «coûts» au lieu du « temps » comme variable dépendante, et ont menés à des conclusions similaires. L'étude a démontrée que, après la mise en place du programme satellite, moins de patients de faible complexité étaient référés de la région du programme satellite au centre hospitalier universitaire, avec une augmentation de la charge de travail infirmier et des coûts.
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Organic food is increasingly available in the conventional food retail, where organic products are offered alongside with various other types of products and compete mainly with conventional and the so-called conventional-plus products. The latter are conventional products displaying particular quality attributes on the product packaging, such as ‘no artificial additives’, or ‘from animal welfare husbandry’. Often, these quality attributes also apply to organic products. Occasional organic consumers might prefer such conventional-plus alternatives that are perceived to be ‘between’ organic and conventional products. The overall objective of this PhD thesis was to provide information about the segment of occasional organic consumers. In particular, the thesis focussed on consumer perceptions and attitudes towards the quality of, and preferences for, organic, conventional and conventional-plus products in two countries: Germany and Switzerland. To achieve these objectives, qualitative and quantitative consumer research was combined in order to explore occasional organic consumers’ perceptions and attitudes as well as to observe their preferences and buying behaviour regarding different types of food products: organic, conventional and conventional-plus products. The qualitative research showed that, depending on single criteria, organic production was both positively as well as negatively assessed by consumers. Consumer perception of organic food was found to be highly selective and primarily focussed on the final stage of the particular production process. A major problem is that consumers are still mostly unfamiliar with factors associated with organic production, have a lack of confidence, and often confuse organic with conventional products. Besides this, consumer expectations of organic products are different from the expectations of conventional products. The quantitative research revealed that attitudes strongly determine consumers’ preferences for organic, conventional and conventional-plus products. Consumer attitudes tended to differ more between organic and conventional choices rather than conventional-plus and conventional choices. Furthermore, occasional organic consumers are heterogeneous in their preferences. They can be grouped into two segments: the consumers in one segment were less price sensitive and preferred organic products. The consumers in the other segment were more price sensitive and rather preferred conventional-plus or conventional products. To conclude, given the selective and subjective nature of consumer perception and the strong focus of consumer perception on the final stage of the food production process, specific additional values of organic farming should be communicated in clear and catchy messages. At the same time, these messages should be particularly focussed on the final stage of organic food production. The communication of specific added values in relation with organic products to improve the perceived price-performance-ratio is important since conventional-plus products represent an interesting alternative particularly for price sensitive occasional organic consumers. Besides this, it is important to strengthen affirmative consumer attitudes towards organic production. Therefore, policy support should emphasise on long-term communication campaigns and education programmes to increase the consumer awareness and knowledge of organic food and farming. Since consumers expect that organic food is regionally or at least domestically produced while they less accept organic imports, policy support of domestic and regional producers is a crucial measure to fill the current gap between the increasing consumer demand of organic food and the stagnation of the domestic and regional organic food supply.
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The understanding of poverty dynamics is crucial for the design of appropriate poverty reduction strategies. Taking the case of Central Sulawesi, we investigate the determinants of both chronic and transitory poverty using data from 264 randomly selected households interviewed in 2005 and 2007. Regarding the US 1$/day poverty line, the headcount index declined from 19.3% in 2005 to 18.2% in 2007. However, we observed an increasing number of people living on less than US 2$/day expressed in purchasing power parity (PPP). The results of the estimated multinomial logit model applied in this study indicate that a lack of non-agricultural employment opportunities and low endowment of social capital are major determinants of chronic as well as transitory poverty in this province of Indonesia. These results are used to draw policy conclusions with respect to the alleviation of transitory and chronic poverty in Central Sulawesi.
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The application of compositional data analysis through log ratio trans- formations corresponds to a multinomial logit model for the shares themselves. This model is characterized by the property of Independence of Irrelevant Alter- natives (IIA). IIA states that the odds ratio in this case the ratio of shares is invariant to the addition or deletion of outcomes to the problem. It is exactly this invariance of the ratio that underlies the commonly used zero replacement procedure in compositional data analysis. In this paper we investigate using the nested logit model that does not embody IIA and an associated zero replacement procedure and compare its performance with that of the more usual approach of using the multinomial logit model. Our comparisons exploit a data set that com- bines voting data by electoral division with corresponding census data for each division for the 2001 Federal election in Australia
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La literatura sobre determinantes de los ingresos laborales ha evolucionado en sus fundamentos teóricos, metodológicos y estimaciones empíricas. Colombia no ha sido ajena a este proceso, pero su evolución, notoria en fertilidad, ha venido relajándose en rigor conceptual: se tiende a considerar a los cuenta propia y asalariados como categorías relativamente semejantes. Para mostrar el efecto de dicha relajación realizamos estimaciones conjuntas de determinantes del ingreso laboral para ocupados asalariados y cuenta propia, y luego las contrastamos con estimaciones más detalladas y desagregadas ilustrando los sesgos efectivos que se generan si no se tienen en cuenta las características laborales de los ocupados cuenta propia y asalariado.
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The resilience of family farming is an important feature of the structure of the farming industry in many countries, due largely to the 'smooth' succession of farms from one generation to the next. The stability of this structure is now threatened by the widening gap between the income expected from farming when compared with non-farming occupations in an economy like Ireland, operating at almost full employment. Nominated farm heirs are increasingly unlikely to choose full-time farming as their preferred occupation. To identify the factors that affect this occupational choice, a multinomial logit model is developed and applied to Irish data to examine the farm, economic and personal characteristics that influence a nominated heir's decision to enter farming as opposed to some non-farming occupation. The results show a significant negative relationship between higher education and the choice of full-time farming as an occupation. The interdependence between education and occupational choices is further explored using a bivariate probit model. The main findings are: the occupational choice and the decision to continue with higher education are made jointly; the nominated heirs on more profitable farms are less likely to pursue tertiary education and therefore more likely to enter full-time farming. The model developed is sufficiently general for studying the phenomenon of succession on farms.
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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.