978 resultados para Ordered probit models
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In multi-vehicle motorcycle crashes, the motorcycle rider is less likely to be at-fault but more commonly severely injured than the other road user. Therefore, not surprisingly, crashes in which motorcycle riders are at-fault and particularly the injuries to the other road users in these crashes have received little research attention. This paper aims to address this gap in the literature by investigating the factors influencing the severity of injury to other road users in motorcyclist-at-fault crashes. Five years of data from Queensland, Australia, were obtained from a database of claims against the compulsory third party (CTP) injury insurance of the at-fault motorcyclists. Analysis of the data using an ordered probit model shows higher injury severity for crashes involving young (under 25) and older (60+) at-fault motorcyclists. Among the not at-fault road users, the young, old, and males were found to be more severely injured than others. Injuries to vehicle occupants were less severe than those to pillions. Crashes that occurred between vehicles traveling in opposite directions resulted in more severe injuries than those involving vehicles traveling in the same direction. While most existing studies have analyzed police reported crash data, this study used CTP insurance data. Comparison of results indicates the potential of using CTP insurance data as an alternative to police reported crash data for gaining a better understanding of risk factors for motorcycle crashes and injury severity.
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Tutkielman tavoitteena on selvittää suomalaisen alkuperäiskarjan lihan potentiaalista kysyntää. Alkuperäiskarjan lihan erikoistuotemarkkinat voivat auttaa pitämään uhanalaiset, kotimaiset karjarodut tuotantokäytössä. Näin ollen erikoistuotemarkkinat voivat auttaa arvokkaiden suomalaisten eläingeenivarojen säilyttämisessä. Koska alkuperäiskarjan lihan tuotannon kannattavuus riippuu lihasta saatavasta lisähinnasta, tutkimuksen tavoitteena on myös tutkia, millainen kuluttajien maksuhalukkuus alkuperäiskarjan lihasta on verrattuna tavanomaiseen lihaan. Tutkimusaineisto kerättiin Maa- ja elintarviketalouden tutkimuskeskuksen ja Kuluttajatutkimuskeskuksen suunnittelemalla kyselytutkimuksella keväällä 2010. Tutkimuksessa käytettiin ehdollisen käyttäytymisen ja ehdollisen arvottamisen menetelmiä ja sen otoskoko on 1623. Kuluttajien ostohalukkuutta ja siihen vaikuttavia tekijöitä tutkittiin sekä binäärisen että ordinaalisen regression malleilla. Kuluttajien maksuhalukkuutta alkuperäiskarjan lihasta ja siihen vaikuttavia tekijöitä tutkittiin grouped data -mallin avulla. Malleissa käytettiin selittävinä muuttujina sosioekonomisten muuttujien lisäksi kuluttajien asenteita ja käyttäytymistä kuvaavia muuttujia. Tutkielman tulosten mukaan jopa 86 % vastaajista ostaisi alkuperäiskarjan lihaa, jos sitä olisi tarjolla kaupoissa. Ostohalukkuutta lisää muun muassa, jos vastaajalla on alle 18-vuotiaita lapsia ja vastaaja arvostaa lähellä tuotettua, paikallista ruokaa sekä ympäristöystävällisyyttä. Miehet ostaisivat alkuperäiskarjan lihaa todennäköisemmin kuin naiset. Suurin osa vastaajista ostaisi alkuperäiskarjan lihaa, jos se olisi samanhintaista kuin tavanomainen liha, mutta noin neljäsosa (23,5 %) vastaajista olisi valmis maksamaan alkuperäiskarjan lihasta korkeampaa hintaa kuin tavanomaisesta lihasta. Maksuhalukkuuteen vaikuttivat positiivisesti muun muassa kuuluminen ympäristöjärjestöön ja korkea tulotaso. Negatiivisesti vaikutti puolestaan esimerkiksi se, että vastaaja on nainen. Keskimääräinen maksuhalukkuus alkuperäiskarjan lihasta oli 6,25 % korkeampi kuin tavanomaisesta lihasta. Maksuhalukkuus alkuperäiskarjan lihasta oli selvästi yhteydessä siihen, kuinka usein vastaaja olisi halukas ostamaan sitä. Maksuhalukkuus oli korkein niillä vastaajilla, jotka haluaisivat ostaa lihaa säännöllisesti.
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Consistent with the implications from a simple asymmetric information model for the bid-ask spread, we present empirical evidence that the size of the bid-ask spread in the foreign exchange market is positively related to the underlying exchange rate uncertainty. The estimation results are based on an ordered probit analysis that captures the discreteness in the spread distribution, with the uncertainty of the spot exchange rate being quantified through a GARCH type model. The data sets consists of more than 300,000 continuously recorded Deutschemark/dollar quotes over the period from April 1989 to June 1989. © 1994.
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A Masters Thesis, presented as part of the requirements for the award of a Research Masters Degree in Economics from NOVA – School of Business and Economics
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Comme la plupart des villes en Afrique subsaharienne, Ouagadougou, capitale du Burkina Faso, a connu au cours de ces dernières décennies une croissance démographique rapide. Cette situation pose de nombreux problèmes d’ordre sanitaire et environnemental. Pourtant, les liens entre la santé et l’environnement immédiat sont encore faiblement étudiés du fait de la qualité des données qui, lorsqu’elles existent, se révèlent peu appropriées. La présente thèse vise à analyser les liens entre l’environnement immédiat et certains symptômes de maladies, plus spécifiquement la fièvre et la diarrhée ; deux problèmes majeurs de santé liés à l’environnement chez les enfants de moins de 5 ans dans les villes d’Afrique subsaharienne. Cette étude se base sur des données de l’Observatoire de population de Ouagadougou (OPO) recueillies entre 2009 et 2010 dans l’objectif d’étudier les inégalités de santé en milieu urbain (notamment les données de l’enquête santé portant sur 950 enfants de moins de 5 ans recueillies en 2010). La thèse décrit d’abord la santé environnementale en milieu urbain en dépassant l’opposition classique quartiers lotis/quartiers non lotis (zones d’habitation formelles/zones d’habitation informelles). Elle s’intéresse ensuite à l’évaluation plus fine des liens entre l’environnement immédiat et la fièvre en tenant compte des facteurs démographiques et socio-économiques pertinents dans l’estimation. Enfin, la thèse approfondit les analyses sur la co-occurrence de la diarrhée et de la fièvre en mettant en évidence les effets conjoints des facteurs environnementaux et démographiques. À l’aide des analyses spatiales basées sur la distance euclidienne, des analyses factorielles et de classification, cette étude décrit le contexte sanitaire des quartiers formels et informels et analyse la pertinence de la dichotomie entre les quartiers lotis et les quartiers non lotis dans les zones suivies par l’OPO. L’étude effectue également des analyses multivariées en recourant respectivement aux modèles logit simple et ordonné pour estimer les effets propres de l’environnement immédiat sur la fièvre et la co-occurrence de la diarrhée et de la fièvre chez les enfants. Les résultats de l’étude montrent que les risques environnementaux sont variables d’un quartier à l’autre, et que les quartiers lotis bien qu’étant les plus pourvus en services urbains de base sont les plus exposés aux dangers environnementaux. Néanmoins, ce constat ne suffit pas pour rendre compte de la vulnérabilité des enfants dans les quartiers lotis que dans les quartiers non lotis, puisque l’accès à l’eau, l’assainissement, la nature du sol, et le niveau d’éducation de la mère sont des facteurs clés dans l’occurrence des symptômes liés à l’environnement immédiat. On note également une hétérogénéité concernant la santé environnementale, notamment dans les zones non loties. En considérant les effets de l’environnement immédiat sur la fièvre chez les enfants, les résultats montrent que ces effets baissent après la prise en compte des variables démographiques, socio-économiques et du quartier de résidence. Les facteurs de l’environnement tels que la gestion des ordures ménagères et celle des eaux usées discriminent significativement la fièvre. Les enfants à Nioko 2 (quartier non loti), par exemple, ont deux fois plus de risque d’avoir eu de la fièvre par rapport à Kilwin (quartier loti). Les effets conjoints des facteurs environnementaux et démographiques sont également mis en exergue dans la co-occurrence de la diarrhée et de la fièvre, même si ces effets diminuent régulièrement avec le nombre des symptômes chez les enfants. Le fait d’être dans un ménage insalubre ou d’avoir le sol extérieur en terre augmente la propension de co-occurrence de la diarrhée et de la fièvre. En revanche, cette co-occurrence chez les enfants diminue significativement avec l’âge. Les effets de l’environnement sur l’occurrence ou la co-occurrence des symptômes existent, quand bien même ces effets diminuent avec la prise en compte des facteurs démographiques et socio-économiques et du quartier de résidence. Les résultats de la thèse plaident pour un effort méthodologique, afin d’affiner la définition des variables de l’environnement en milieu urbain.
Vignettes and self-reported work disability in the United States: Correction of report heterogeneity
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Subjective measures of health tend to suffer from bias given by reporting heterogeneity. however, some methodologies are used to correct the bias in order to compare self-assessed health for respondents with different sociodemographic characteristics. One of the methods to correct this is the hierarchical ordered probit (hopit), which includes rates of vignettes -hypothetical individuals with a fixed health state- and where two assumptions have to be fulfilled, vignette equivalence and response consistency. this methodology is used for the self-reported work disability for a sample of the united states for 2011. The results show that even though sociodemographic variables influence rating scales, adjusting for this does not change their effect on work disability, which is only influenced by income. the inclusion of variables related with ethnicity or place of birth does not influence the true work disability. however, when only one of them is excluded, it becomes significant and affects the true level of work disability as well as income.
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This paper proposes a simple Ordered Probit model to analyse the monetary policy reaction function of the Colombian Central Bank. There is evidence that the reaction function is asymmetric, in the sense that the Bank increases the Bank rate when the gap between observed inflation and the inflation target (lagged once) is positive, but it does not reduce the Bank rate when the gap is negative. This behaviour suggests that the Bank is more interested in fulfilling the announced inflation target rather than in reducing inflation excessively. The forecasting performance of the model, both within and beyond the estimation period, appears to be particularly good.
Body mass index as a standard of living measure: a different interpretation for the case of Colombia
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We analyze the Body Mass Index (BMI) in a distinct way of its traditional use and it lets us use it as a proxy of standard of living for the case of Colombia. Our approach is focused on studying how far the people are from the normal range and not on the score of each one and this lets us to treat equally extreme cases as severe thinness and obesity. We use a probabilistic model (Ordered Probit) that evaluates the probability of being within the normal range or another level. We found that socioeconomic variables have a significant effect on the dependent variable and that there are no linear effects. Besides, people with difficulties for walking and adults have less probability of having a normal BMI.
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We analyze the determinants of subjective returns of higher education in Colombia. The information on expectations has been collected in categories, motivating the use of interval regression and an ordered probit approaches for modeling the relationship between beliefs and measures of ability, conditioning on individual, school and regional covariates. The results suggest that there are considerable differences in the size of the expected returns according to some population groups and a strong dominance of college against technical education. Gender gaps disappear in college education but it is found that girls tend to believe that professional wages are more concentrated into higher income categories than boys. Finally, it seems that Colombian students overestimate the pecuniary returns to education.
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It is becoming increasingly difficult for the public to attempt to assess risks using traditional methods such as smell, taste or other physical attributes of food. The existence of extrinsic cues such as the country of origin (COO) of food can help to make food purchase decisions easier for consumers. However, the use of extrinsic cues depends heavily on the extent to which consumers trust such signals to be indicative of quality or safety, which in turn depends on the credibility behind that cue. This paper aims to examine consumers association of domestically produced food with increased food safety standards and the association of COO and food safety information with socio-demographics and other aspects of consumer psychology such as attitudes, risk perception and trust. Using an ordered probit model, domestic production is examined as an extrinsic cue for food safety by looking at the relationship with trust in food safety information provided by national food standards agencies (NFSAs) and other socio-demographic characteristics, based on nationally representative data from 2725 face-to-face interviews across five European countries. Results suggest that domestic production of food is an extrinsic cue for food safety and as consumers place increasing importance on food safety they are more interested in food produced in their own country. This, coupled with consumer trust in a strong, and independent national food standards agency, suggests the potential exists for the increased consumption of domestically produced foods.
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This study suggests a statistical strategy for explaining how food purchasing intentions are influenced by different levels of risk perception and trust in food safety information. The modelling process is based on Ajzen's Theory of Planned Behaviour and includes trust and risk perception as additional explanatory factors. Interaction and endogeneity across these determinants is explored through a system of simultaneous equations, while the SPARTA equation is estimated through an ordered probit model. Furthermore, parameters are allowed to vary as a function of socio-demographic variables. The application explores chicken purchasing intentions both in a standard situation and conditional to an hypothetical salmonella scare. Data were collected through a nationally representative UK wide survey of 533 UK respondents in face-to-face, in-home interviews. Empirical findings show that interactions exist among the determinants of planned behaviour and socio-demographic variables improve the model's performance. Attitudes emerge as the key determinant of intention to purchase chicken, while trust in food safety information provided by media reduces the likelihood to purchase. (C) 2006 Elsevier Ltd. All rights reserved.
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Pesticide residue in vegetables is a major food safety issue in Thailand. A range of vegetable products (organic/pesticide-free/ hydroponic) has emerged in Thai markets that guarantee compliance with maximum residue limits. The Government of Thailand is eager to extend the benefits of this suite of alternative vegetables to the entire population, particularly the semi-urban/rural segments that are often bypassed by such speciality products. However, little information is available to guide such an effort, particularly with regard to up-country consumer attitudes, shopping and consumption habits and willingness to pay premiums for such produce. This research aims to fill this gap in knowledge. It reports the results of a survey of vegetable consumption and shopping habits and attitudes of 608 consumers in northeast Thailand. Willingness to pay premiums for pesticide residue limit compliant vegetables is also assessed by using a contingent valuation method, and determinants of willingness to pay are examined using an ordered probit empirical model. Results indicate that, given adequate awareness of relative risks, even up-country consumers are willing to pay market premium levels for these products, and that inadequate availability, rather than lack of demand is the constraining factor. Willingness to pay is found to increase with income, age and supermarket sourcing of vegetables. We also discuss the challenge of improving availability at mainstream outlets.
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Policy makers in the European Union are envisioning the introduction of a community farm animal welfare label which would allow consumers to align their consumption habits with their farm animal welfare preferences. For welfare labelling to be viable the market for livestock products produced to higher welfare standards has to be sufficiently segmented with consumers having sufficiently distinct and behaviourally consistent preferences. The present study investigates consumers’ preferences for meat produced to different welfare standards using a hypothetical welfare score. Data is obtained from a contingent valuation study carried out in Britain. The ordered probit model was estimated using Bayesian inference to obtain mean willingness to pay. We find decreasing marginal WTP as animal welfare levels increase and that people’s preferences for different levels of farm animal welfare are sufficiently differentiated making the introduction of a labelling scheme in the form of a certified rating system appear feasible.
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A teoria de escolha do portfólio ótimo, desenvolvida a partir da análise da média-variância de Markowitz (1952) deu início ao estudo de vários destes conceitos. A conclusão definitiva deste modelo é que todos os investidores que levam somente em conta a média e o desvio padrão para análise dos investimentos terão o mesmo portfólio de ativos de risco. Investidores conservadores combinarão este portfólio com ativos livres de risco para compor uma carteira menos arriscada. Investidores moderados reduzirão a quantia em ativos livres de risco, aumentando, assim seu risco total. E investidores agressivos podem até contrair empréstimos para obter um portfólio mais arriscado. Os administradores financeiros têm, tradicionalmente, resistido ao simples conselho sobre investimentos embutido nesta teoria. Esta resistência pode, até certo ponto, ser justificada pela necessidade de cada investidor construir seu portfólio refletindo suas preferências e necessidades particulares. Portanto, a gestão da riqueza é um processo direcionado pelas necessidades do indivíduo e não pelos produtos disponíveis. Logo, a análise acadêmica tradicional de escolha do portfólio ótimo precisa ser modificada com o intuito de tratar tais individualidades. O objetivo deste trabalho é usar a base de dados para comparar os resultados empíricos sobre alocação de portfólio à luz da teoria de investimentos com os resultados obtidos através de um questionário respondido pelos funcionários da Souza Cruz, onde utilizaremos um modelo de regressão ordered probit, que prevê a separação em três níveis, dependentes entre si.
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This study aims to the evaluate the determinants for rural households northeastern be pluriactive, in 2011. For this, at first, we conducted a review of national and international literature in order to get beyond the theoretical part which refers to the study of pluriactivity identify possible determinants of the phenomenon. In this rescue, it was the observed determinants could be macroeconomic in nature and / or microeconomics. Therefore, it became necessary to describe the characteristics of the region under study, the Northeast. In order to identify the determinants were two estimated Probit models, one based on the literature review and the second with a variable characteristic of the Northeast, the transfers. For this, we used the PNAD in 2011. The results indicate both the microeconomic determinants are : gender, race, age, years of education, hours worked, number of family members, per capita income, transfer the macroeconomic in nature: living conditions (water, energy, sanitation ), housing location. In addition to identifying the determinants, the Econometric model allows to know the probability of each variable on the dependent variable, which stood out: the transfer variable, gender, per capita income, number of family members, housing conditions and housing location. Therefore, it is concluded that it is the set of determinants (macro and micro) allow rural families become northeastern pluriactive. However, one can not fail to consider may also have other determinants were not captured due to the availability of data, which may be indications for future studies. In summary, the pluriactivity in the Brazilian Northeast is a phenomenon distinct from found in Europe and southern Brazil. It is a pluriactivity survival that is part of the strategies of rural households in the Northeast to ensure their social reproduction amid the poverty of the region