Modeling Disinterest and Dislike: A Bounded Bayesian Mixed Logit Model of the UK Market for GM Food

Mixed logit models represent a powerful discrete choice analytical model but require assumptions about the functional form of the parameter distributions. The use of unbounded distributions, such as the normal distribution, may be regarded as unsuitable where theory indicates that all are negatively affected by increases in an attribute, such as price. Bounded distributions such as the triangular and log-normal are unable to model the case where a section of the population is indifferent towards an attribute, while the remainder are negatively disposed toward it. Train and Sonnier’s bounded mixed logit model accommodates these features and is employed in this paper. A censored normal and Johnson’s S_b distribution are used to model preferences in the UK for food attributes, including price and GM technology. Bi-modal distributions are identified regarding GM food: some are unlikely to ever consume it, some are close to indifference and willing to consume at relatively small discounts while the remainder are fairly unresponsive to further price reductions.     

城乡居民收入差距的动态演变:1988～2002年

中国城乡居民收入差距已经引起广泛关注。文章以住户调查数据为基础,利用泰尔指数分解、G.Fields分解、Blinder分解、分位回归分解等多种方法讨论了1988年、1995年和2002年“城乡”因素本身对城乡居民收入差距的贡献。这些分解结果表明我国的城乡差距较显著并在不断扩大;而且城乡差距更不利于农村中的低收入人群。     

泰山旅游需求时空分布规律及旅游者行为特征的初步研究

泰山旅游需求存在着明显的时空分布规律．调查显示．游人数量的日变化、周变化和年内变化十分显著；客源地主要分布于山东及其周边省市；旅游区内部以泰山中路和岱顶的需求强度最大。最后对旅游交通方式、旅游消费、旅客职业构成双重游率等旅游者行为特征进行了分析。     

Coping with Technological Change: The Role of Ability in Making Inequality so Persistent

This study provides an explanation to the evolution of wage inequality over the last 30 years and supports this explanation with evidence. A faster rate of technological progress introduces new unknown elements at the workplace. The need to cope with the unknown accentuates the role of ability and thus increases wage inequality within and between education groups. Inasmuch as education is an irreversible investment project the rise in within group inequality BOOSTS UP the rise of between group inequality. Guided by this theory we turn to the PSID for evidence. Using parents' education to approximate child's ability we show the following set of results: (a) Controlling for education of the child, parents' education contributed much more in the 1980s to his wage growth than in the 1970s. (b) The correlation between the parents' and the child's education increases from the 1970s to the 1980s. (c) The return to college education for an individual with no ability rents did not change—it remains steady at the 23 percent. (d) Facts (a)–(c) CANNOT be attributed to the impact of parent's income. It is parents' education and not parents' income that is more relevant for son's economic outcomes in the 1980s.     

基于顾客需求的物流地产价值创新

借助对物流地产与商业地产、工业地产的比较分析,探讨了物流地产的内涵,对普洛斯的物流地产运作模式进行了案例分析,并对其物流地产的价值创新战略进行了阐释。     

基于客户价值的配送企业价值链分析与重组

指出了传统价值链思想的局限性，从企业获得持续竞争优势出发，提出了基于顾客价值的价值链分析方法，并将其应用到配送企业价值链重组中，分析了虚拟配送企业价值链的特点，并对虚拟配送企业提高客户价值的方法进行了讨论。     

装备维修器材分配供应方法研究

装备维修器材的分配供应是实现对部队维修器材保障的关键一环，本文通过分析其分配供应的具体过程，对每一环节建立了切合实际、方便操作使用的数学模型，可为装备维修器材保障业务人员提供科学的决策依据，从而达到军事效益和经济效益的双赢的目的。     

Simulation driven inferences for multiply imputed longitudinal datasets*

In this article, we demonstrate by simulations that rich imputation models for incomplete longitudinal datasets produce more calibrated estimates in terms of reduced bias and higher coverage rates without duly deflating the efficiency. We argue that the use of supplementary variables that are thought to be potential causes or correlates of missingness or outcomes in the imputation process may lead to better inferential results in comparison to simpler imputation models. The liberal use of these variables is recommended as opposed to the conservative strategy.     

配送计划的优化编制方法

讨论了在时间、距离和载重量等多种约束条件下，编制配送计划的优化方法。先给出配送问题的数学模型，并设计了一个带时间和距离约束条件的启发式算法来求解该模型，求得问题的近似解；然后再采用分枝定界法得到配送问题的最优解：最后，考查近似解与最优解在总的运行距离的相对误差，以此检验这个近似解的有效性。     

Evolution of trade patterns in the new EU member states

The paper analyses the evolution of the trade specialization pattern in the new EU member states. Relying on the empirical approach of the Markov transition matrices it analyses both the changes in the external shape of the distribution of comparative advantages and the intra‐distribution dynamics. The new members show a dynamic trade pattern: they gained comparative advantages relatively fast in sectors in which they were lagging behind at the beginning of the transition, notably in some ‘high tech’ products. In addition, many specialization improvements occurred in those items for which world demand expanded at the fastest rate over the nineties.