基于Multinomial Logit模型的美国北卡罗莱纳州慢行交通事故严重程度分析

为分析慢行(自行车与行人)交通事故严重程度的显著性影响因素,将交通事故分为仅财产损失事故、潜在伤害事故、非伤残事故、伤残事故、死亡事故5类,从人、车、路、环境4个层次选出11个自变量,以交通事故严重程度为因变量,基于Multinomial Logit模型计算每个变量对慢行交通事故严重程度的边际效应。结果表明,驾驶员性别、驾驶员饮酒状态、行人年龄、道路特征、路面状态、一天内发生时间、光线条件、年平均日交通量、地形等9个变量均与道路交通事故严重程度显著相关。

Ethnobotanical profiling of the medicinal flora of Kotli,Azad Jammu and Kashmir,Pakistan:Empirical reflections on multinomial logit specifications

Objective:To report the indigenous people's uses of plants from a multidimensional perspective in a remote area where strong ethnobotanical cultural practices prevail. Methods:An ethnobotanical survey was conducted in the field during 2014-2016. Ethnobotanical data were gathered from 182 informants through oral interviews and semi-structured questionnaires. The distribution of plants was explored using both descriptive and graphical methods. Further,a Multinomial Logit Specification was applied to find out the probability of the occurrence of diverse utilization of plants in multipurpose domains. Results:The study identified 202 plant species distributed among 71 families and 156 genera. Ethnobotanical data indicate that there are more medicinal(36.96%) uses of plants as compared to all other use categories. The output from the Multinomial Logit Specifications(MLS) model reveals that perennial and non-woody plants are exploited more for medicinal and food uses than annual and woody plants. In the context of ethnomedicinal uses,aerial plant parts particularly leaves are more extensively used for the preparation of herbal recipes as compared to underground parts. Conclusions:The results of the study emphasize the need to create awareness among the local communities about the conservation status of plant species in order to maintain a sustainable resource of plant-derived materials into the future. The novel econometric approach employed in this study adds a new insightful methodology to the existing body of literature in the field of ethnobotany. We strongly recommend conservation measures,alongside phytochemical and pharmacological studies on the useful plant species identified in this study in order to ensure their sustainable and effective utilization.

Optimal model averaging estimator for multinomial logit models

In this paper,we study optimal model averaging estimators of regression coefficients in a multinomial logit model,which is commonly used in many scientific fields.A Kullback-Leibler(KL)loss-based weight choice criterion is developed to determine averaging weights.Under some regularity conditions,we prove that the resulting model averaging estimators are asymptotically optimal.When the true model is one of the candidate models,the averaged estimators are consistent.Simulation studies suggest the superiority of the proposed method over commonly used model selection criterions,model averaging methods,as well as some other related methods in terms of the KL loss and mean squared forecast error.Finally,the website phishing data is used to illustrate the proposed method.

Coopetition Between TTA and OTA Based on Multinomial Logit Choice Model

This paper proposes a framework to analyse the impact of online travel agency(OTA)when it steps into an original market of a traditional travel agency(TTA).Based on the multinomial logit choice model,the demand model and the profit model are presented.Then,the demand squeeze,the total demand increase and the cooperation range of wholesale price are analysed.From the analysis,the results indicate that:(1)OTA can increase the demand of the whole market while it squeezes the demand of TTA;(2)The demand squeeze,total demand increase and the range of cooperation wholesale price are all positive with the perceived value from OTA and negative with the perceived value from TTA.(3)The more immature the market is the more necessary for TTA to cooperate with OTA.In addition,numerical example and sensitivity analysis of perceived value and price are presented to illustrate the demand squeeze,demand increase and cooperation range of wholesale price.

Generalized nested logit-based stochasticuser equilibrium model with distance constraint of electric vehicles

Considering the range anxiety issue caused by the limited driving range and the scarcity of battery charging stations,the conventional multinomial logit(MNL)model with the overlapping path issue was used in route choice modeling to describe the route choice behavior of travelers effectively.Furthermore,the generalized nested logit-based stochastic user equilibrium(GNL-SUE)model with the constraints of multiple user classes and distance limits was proposed.A mathematical model was developed and solved by the method of successive averages.The mathematical model was proven to be analytically equivalent to the modified GNL-SUE model,and the uniqueness of the solution was also confirmed.The proposed mathematical model was tested and compared with the GNL-SUE model without a distance limit and the MNL-SUE model with a distance limit.Results show that the proposed mathematical model can effectively handle the range anxiety and overlapping path challenges.

考虑顾客选择行为的BOPS自提门店个性化推荐

针对全渠道零售中的BOPS(在线购买门店提货)模式,给出了考虑顾客选择行为的自提门店推荐方法。此方法构建了结合商圈、距离以及预计送达时长的不同收货方式下顾客的效用函数,通过MNL选择模型来刻画顾客的选择行为,建立考虑顾客选择行为的以零售商利润最大化为目标的混合整数规划模型。其次,将模型转换成易于求解器求解的混合整数二阶锥规划模型。数值实验表明本文提出的自提门店的推荐方法可提升零售商的利润。最后,探讨了预计送达时长、顾客的距离敏感度与收益的关系。数值实验结果表明,零售商的总利润与预计送达时长呈正相关关系,零售商的总利润与顾客对距离的敏感度呈负相关关系。

Navigating Market Choices: Understanding Carrot Market Outlet Selection among Smallholder Farmers in Kenya

This research delves into the hurdles and strategies aimed at augmenting the market involvement of smallholder carrot farmers in Nakuru County, Kenya. Employing a Multinomial Logit (MNL) model, it scrutinizes the factors influencing the selection of marketing outlets among carrot farmers. The findings unveil that a significant majority (81%) of surveyed farmers actively participate in diverse market outlets, encompassing the farm gate, cleaning point, local market, external market, and export market. Notably, pivotal buyers include aggregators, brokers, wholesalers, retailers, and consumers, with transactions predominantly occurring at the farm level. Additionally, the analysis discerns substantial influences of socio-economic characteristics, experiential factors, and geographical proximity on farmers’ choices of market outlets. Specifically, gender, age, land size, farming experience, and distance to markets emerge as critical determinants. Moreover, the study delves into the examination of market margins along the carrot value chain, shedding light on the potential profitability of carrot farming in the region. Remarkably, higher average gross margins are identified in export and external markets, signaling lucrative prospects for farmers targeting these segments. However, disparities in profit distribution between farmers and traders underscore the necessity for interventions to ensure equitable value distribution throughout the value chain. These findings underscore the imperative for tailored interventions to tackle challenges and foster inclusive agricultural development. Strategies such as farmer organizations, contracting, and vertical integration are advocated to enhance market access and profitability for smallholder carrot farmers. Thus, this study enriches our comprehension of the dynamics within carrot value chains and provides valuable insights for policymakers and development practitioners aiming to uplift rural livelihoods and bolster food security.

重大道路交通事故严重程度影响因素分析

基于事故数据的道路交通事故严重程度影响因素分析是制定交通安全对策的基础,不同类型、算法的建模方法对事故严重程度影响因素的拟合精度不同,提取的显著影响因素存在差异。为提高研究结果准确性,以某地区人员伤亡和重大财产损失的道路交通事故信息为数据集,运用Multinomial Logit、决策树、神经网络3类方法分别建模分析事故严重程度影响因素。鉴于3类模型输出的显著变量存在差异,通过交叉对比验证进行显著影响因素判别。研究发现,事故认定原因、事故发生纵向位置、事故发生道路类型等是事故严重显著影响因素,研究成果有效修正了单一模型的偏差,对精准制定事故改善对策具有指导意义。

One size fits all? Contract farming among broiler producers in China

Contract farming has been increasingly found to benefit smallholders in developing countries, yet much less is known about its role in the poultry industry where economies of scale could be more prominent. This study aims to narrow this gap by analysing the choice of contract farming among Chinese broiler producers using a nationally representative survey. Simply cost-benefit analysis and multinomial logit regression modelling are jointly employed to explain contract farming decision making especially among small producers. In contrast to many recent studies, we find that small producers, though not passively excluded, usually opt out of contract farming due to limited profitability when large producers are coexistent. Such relationship is appropriately identified through a control function approach to correct for possible endogeneity. Therefore, contract farming may not help achieve higher welfare goals for small broiler producers who actually instead seek alternative market opportunities that better realise their comparative advantages.

Analysis of high-speed rail and airline transport cooperation in presence of non-purchase option

We study cooperation between the airline and high-speed rail(HSR) sectors by formulating their joint profit as a maximization problem using a multinomial logit choice model in a three-node setting. We allow the nonpurchase option as an outside option available to consumers. The demand for each choice is not only a function of the price but also the service quality, such as the total trip time, frequency of service, and ease of connecting from the hub to a nearby HSR station. As a result, the following findings are presented. First, regardless of the service quality of either sector and the non-purchase option,cooperation decreases the total volume of the domestic market of a country. Second, when the attractiveness of the outside option is high, the HSR and air sectors can prevent a large reduction in the total volume by cooperation in the connecting market. However, this is not the case in the domestic market. Third, if the non-purchase quality in the domestic market is high, then cooperation increases the social welfare of the whole market. If the non-purchase quality is low, then cooperation increases the welfare of the whole market only in cases where the number of potential customers in the connecting market is relatively large. We also show the effect of improving air–rail service quality on each market share and on the total profit.

A socioeconomic approach to the profile of microcredit holders from the Hispanic minority in the USA

The subject of this study is the microcredit market in the USA,more specifically in Florida.The justification for choosing this specific state is the massive presence of the Hispanic population.This will facilitate a generalization of the obtained results to the microcredit market in Latin American countries.Thus,the objective of this study is to analyze the profile of microcredit holders and their companies from socioeconomic and financial points of view.As our data also consider the degree of repayment of the microloans included in the sample,the clients’profile is related to the punctuality or default of their corresponding loan repayments using the methodology of multi-nomial logit regression.The variables used in this study refer to personal information concerning borrowers(gender,age,education level,and marital status),the economic situation of their respective companies(closeness to the lender,number of workers,and revenues),and the characteristics of granted loans(principal,term,and purpose).However,the results of the regression show that only two variables are significant at the 5%significance level:the borrower’s age,which has a positive effect on repay-ment punctuality,and the loan term,which exhibits a negative effect.The findings of this study have clear implications,as they can help lenders design suitable microloans adjusted to customer profiles.Finally,future research should include other demograph-ics and characteristics of affected companies.

Key factors contributing to crash severity at highway-rail grade crossings

The purpose of this paper is to develop and com- pare the preferred multinomial logit （MNL） and ordered logit （ORL） model in identifying factors that are important in making an injury severity difference and exploring the impact of such explanatory variables on three different severity levels of vehicle-related crashes at highway-rail grade crossings （HRGCs） in the United States. Vehicle-rail crash data on USDOT highway-rail crossing inventory and public crossing sites from 2005 to 2012 are used in this study. Preferred MNL and ORL models are developed and marginal effects are also calculated and compared. A majority of the variables have shown similar effects on the probability of the three different severity levels in both models. In addition, based on the Akaike information criterion, it is found that the MNL model is better than the ORL model in predicting the vehicle crash severity levels on HRGCs in this study. Therefore, the researchers recommend the use of MNL model in predicting severity levels of vehicle-rail crashes on HRGCs.

A study of the factors affecting mobile money penetration rates in the West African Economic and Monetary Union (WAEMU) compared with East Africa

According to the 2017 Global Financial Inclusion(Global Findex)database,the average penetration rate of mobile money accounts in East Africa is higher than that of the WAEMU.This study attempts to understand the factors driving the adoption and the use of mobile financial services in the WAEMU compared to East Africa.To achieve this,micro-level data from the 2017 Global Findex database are used to perform probit and multinomial logit estimations.The findings reveal that the same determinants influence the adoption and use of mobile money accounts across the populations of both groups of countries,specifically those related to the least vulnerable social categories(i.e.,males,older,more educated,richer and part of the workforce).Therefore,in comparison to East Africa,the delay in the penetration of mobile money accounts observed in the WAEMU may be attributed to insufficient policies for increasing the awareness of the benefits of mobile financial services.The study recommends that governments in WAEMU countries promote the use of mobile money accounts among the working-age population(adults aged between 25 and 64)through the improvement of individual income level,and the introduction of incentives into the education system to encourage their population to attain higher levels of education.

Studying on equilibriums between price and QoS in multi-provider overlay access networks

From the viewpoint of game theory, this paper proposes a model that combines QoS index with price factor in overlay access networks, and uses the multinomial logit （MNL） to model the choice behaviour of users. Each service class is considered an independent and competitive entity offered by each provider, which aims at maximizing its own utility. Based on noncooperative game, we prove the existence and uniqueness of equilibriums between QoS levels and prices among various service classes, and demonstrate the properties of equilibriums. Finally, these results are verified via ntunerieal analysis.

Factors Explaining the Dynamics of Agricultural Technological Innovations Adoption: Evidence from Senegal’s Rain Maize Farmer

This paper analyzes the adoption dynamics of improved rainfed maize seeds disseminated in Senegal in 2013 by the West African Agricultural Productivity Program (WAAPP). We group maize producers into five groups (non-adopters, laggards/abandoners, late adopters, followers and pioneers/innovators) and take into account the heterogeneity of unobservable characteristics of the producers. In the pioneers/innovators group, the availability of labour, household size, shocks, and frequency of access to advice positively influence adoption, whereas financial constraints and high numbers of plots reduce the probability of adoption. Producers in the followers’ category tend to be older and more educated than those in the other categories. However, food insecurity and shocks such as diseases hamper adoption. For the group of late adopters, household size and available storage infrastructures explain adoption. However, the number of plots and shocks reduces their probability of adoption. Laggards tend to face shocks and food insecurity. The authors recommend to consider the dynamics of the adoption of technological innovations and heterogeneity of the characteristics of adopters groups in future research. They also recommend farmers to increase their adoption rate of the “Early Thai” and “Suwan 1” seed varieties thanks to their higher yields compared to traditional varieties. Also, a higher adoption rate would positively impact the food security of maize farmers in Eastern Senegal and High Casamance, especially in terms of availability. Other studies measuring the number of years needed for large-scale adoption of improved seed varieties should be conducted.

The Effect of Family Planning Methods on Food Security in Oyo State, Nigeria

This study affirms the effect of family planning on rural household food security. The major thrust of this research identified socio-economic characteristics of respondents, various family planning methods used, benefit of use and factors influencing household food security in the study area. The research was carried out in 4 Local Government areas （LGAs） of Oyo state, where five communities each were randomly selected from the LGAs. A total of 272 households were sampled from the 20 communities. Descriptive and multinomial logit regression were used to analyse data collected. Findings revealed that 64.4% of the respondents were female, mean age was 40 years; about 80% of them were married and most of them had formal education with average of 10years spent in school. Result further revealed that that most of the respondents adopt artificial method of family planning. Sex, marital status of respondent, number of children; primary occupation, traditional method, natural method and artificial method of family planning were the factors influencing household food security status. It was recommended that rural household should be enlightened on the advantages of the use of family planning to improve their household nutritional intake level as well as standard of living.

Pastoralists’ Adaptation Strategies to Climate Change and Determinant Factors in Korahey Zone, Ethiopia

Climate change is a global phenomenon that involves the long-term fluctuation of the earth’s climate system. Specifically, climate change is acknowledged as a vital challenge to pastoralist production systems. However, limited research attention was given to exploring the determinants of climate change adaptation strategies in the southeastern part of Ethiopia. Thus, the study tried to assess the predictors of pastoralists’ climate change adaptation strategies in the Korahey zone of Ethiopia. The study was based on a survey of 215 representative pastoralist households were randomly selected from the three districts of the Korahey zone. To achieve the objective, household questionnaire surveys, key informant interviews, and focus group discussions were conducted to collect data at the household as well as the district level. Data were analyzed using descriptive statistics like percentage, frequency, mean, and inferential statistics (multinomial logit model). Multinomial logit was employed to analyze the determinant factors of pastoralists’ adaptation strategies to climate change. The finding shows that household pastoralists adopt different climate change adaptation strategies in their locality;from this herd diversification (10.7%), storage of fodder (14.4%), mobility (23.7%), Livestock off-take (12%), saving scheme (8.8%) and household and herd splitting (15.3%) are the major pastoralists’ adaptation strategies to climate change in the study area. The results of the multinomial logit model show that sex, age, family size, access to climate information, access to credit services, access to extension services and livestock ownership were identified as the major determinants factors of climate change adaptation strategies in Korahey zone. The study recommended that the local government, planners and decision-makers should give awareness regarding the role of information in the pastoralists’ adoption of climate change adaptation strategies and enhance extension services to support pastoralists in their adaptation efforts.

Modelling of Active and Latent Attributes Based on Traveler Perspectives: Case of Port City of Douala

A growing stream of study stresses the relevance of subjective elements in understanding the hierarchy of preferences that underpin individual travel behavior. The purpose of this study is to evaluate the impact of various factors on mode choice. To achieve this, a multinomial logit model (MNL) was used to analyze the relationships between mode choice and three classes of attributes;Combined Active and Latent, Active only and Latent only attributes. The data used are derived from surveys in the port city of Douala, Cameroon as a case study. Results stipulated that, the combined attributes model performed better than both active only attributes and latent only attributes models. Likewise, latent only attributes model performed better than active only attributes model. The advantage of modelling all three groups is for better selection of the most relevant attributes, and this is very relevant in understanding travel behavior of individuals and mode choice decisions.

Passenger Choice Behavior between Direct and Transit Flights——A Case Study on Passengers Using Hub Airports in the Northeast Asian Region

This study analyzes air passenger route choice behavior for long-haul inter-continental travel. It employs the SP （state preference） technique and logit modeling to investigate the impact of route development via neighboring countries in the region. With the Japanese government pursuing an increase in international routes at Haneda International Airport, and the Chinese government planning to construct Beijing Capital Second International Airport by 2019, the competition among airports to serve as hubs in Northeast Asia will increase significantly. Korean passengers will have a greater number of route choices when traveling to North America or Europe, utilizing not only direct flights from Incheon International Airport but also flights via Tokyo or Beijing area airports including Haneda International Airport, Narita International Airport, Beijing Capital International Airport and Beijing Capital Second International Airport. Accordingly, passengers will choose among the alternatives by considering fares and flight times. As such, it is essential for airports to offer flights with competitive prices for transit passengers to become successful competitive airports in the region. Therefore, it will become more important for market decision makers to strive toward more attractive ticket prices and better route network quality.

Factors affecting college students’attitudes towards carpooling

As a sustainable mode of travel,carpooling is an effective solution to environmental and energy problems,but it has not been fully utilized.The research on carpooling attitudes,especially for college students,still needs to be improved.In response to this problem,this paper aims to investigate the effect of personal attributes,travel attributes,attitude attributes and other attributes of students on carpooling attitudes in China.To collect the data,an online questionnaire survey was implemented at Shenzhen University,and 514 students participated.Based on the samples,the multinomial logit model is used to explore the contribution of all variables.The model results showed that personal attributes such as sex and age had no significant effect on the attitude of college students towards carpooling.The safety of carpooling and its high cost make college students have a neutral attitude towards it.The most concerning factor for college students in carpooling is comfort.These findings can provide valuable suggestions for measures to be taken in response to different attributes affecting students’attitudes and are particularly important for the university and government to make optimal decisions to motivate students to select carpooling.