Stochastic approximation methods in nonlinear regression models 1

The brief review of theory of stochastic approximation methods in nonlinear regression models is given. Particularly the situation when regression function has several extrema is discussed. The special attention is given to recent on the weakening of conditions on distrubances and on regression function, which guarantee the convergrence of the provedures. The problems of asymptotically optimal choice of procedures, parameters and applications to the parametric estimation are touched too.     

唐代消费结构优化趋势及其实现途径研究

有唐一代,经济发展,商业繁荣,极大地促进了消费经济的发展.尤其是唐盛世时期,社会总供给渐次大于社会总需求,城乡居民的收入水平和消费水平有了很大提高,人口的消费需求与日俱增,促进了商品供给结构的优化和商品性农业结构的调整.随着商品性消费比重越来越高,唐代居民生存性实物消费品的消费比重下降,精神娱乐性消费和服务性消费比重相应增大,进而促进了消费结构的优化、升级.     

Stochastic Optimal Control for Staffing and Backlog Policies in a Two‐Stage Customized Service Supply Chain

Motivated by an oilfield services industry case study, we investigate the dynamic behavior of customized service supply chains by developing a two‐stage serial staffing model. Each stage holds no finished goods inventory, but rather only backlogs that can be managed by adjusting staffing levels. We develop optimal control policies to balance backlog costs against hiring and firing personnel costs'assuming shared backlog information—under both centralized and decentralized control. We examine when there is sufficient economic incentive for two completely decentralized stages to begin: (1) to share backlog information without centralizing control, or (2) to completely centralize control. These switching points are determined by the relative service and personnel costs of the two stages. From these results, we show that decentralizing control in many cases does not materially worsen performance, so long as information is shared. Moreover, in some cases, even sharing information is of only marginal benefit.     

Joint Life‐Cycle Dynamics of New and Remanufactured Products

Many products considered for remanufacturing are durables that exhibit a well‐pronounced product life cycle—they diffuse gradually through the market. The remanufactured product, which is a cheaper substitute for the new product, is often put on the market during the life cycle of the new product and affects its sales dynamics. In this paper, we study the integrated dynamic management of a portfolio of new and remanufactured products that progressively penetrate a potential market over the product life cycle. To this end, we extend the Bass diffusion model in a way that maintains the two essential features of remanufacturing settings: (a) substitution between new and remanufactured products, and (b) a constraint on the diffusion of remanufactured products due to the limited supply of used products that can be remanufactured. We identify characteristics of the diffusion paths of new and remanufactured products. Finally, we analyze the impact of levers such as remanufacturability level, capacity profile and reverse channel speed on profitability.     

商品的价值遗漏与现实修正

无论是劳动价值论还是主观效用论，对商品的本源价值均有疏忽和遗漏，这也是经济学价值理论的重要缺陷。产生商品价值遗漏的主要原因包括两方面:自然生态作为商品本源价值的提供方，其价值主体易于被忽略;自然生态提供的初始价值，在商品交易中易于被忽视。商品的价值遗漏给生态与自然、经济与社会以及市场逐利主体的行为，都带来严重不利影响。对商品价值遗漏的现实修正，应当充分发挥党政的主导意识功能、法制边界的主线与底线功能、社会督导的公共保障功能、个人修为的基础性自动自发功能、科技力量的根本能动作用等五大战略性功能与作用。     

A Novel Estimation Approach for Mixture Transition Distribution Model in High-Order Markov Chains

A transformation is proposed to convert the nonlinear constraints of the parameters in the mixture transition distribution (MTD) model into box-constraints. The proposed transformation removes the difficulties associated with the maximum likelihood estimation (MLE) process in the MTD modeling so that the MLEs of the parameters can be easily obtained via a hybrid algorithm from the evolutionary algorithms and/or quasi-Newton algorithms for global optimization. Simulation studies are conducted to demonstrate MTD modeling by the proposed novel approach through a global search algorithm in R environment. Finally, the proposed approach is used for the MTD modelings of three real data sets.     

The Role of the Statistician: Scientist or Shoe Clerk

A carnival game is described in which a player rolls eight dice or eight marbles into holes. To win, the player must obtain a favorable outcome on a number of plays. The probability distribution for the outcome of a single play is discussed. The distribution of a winning combination of outcomes is discussed and approximated. These probabilities show that the game is essentially unbeatable.     

商品包装文字设计的路径探讨

通过分析商品包装中文字设计的不同形式、风格和内容,指出包装中文字设计的目的和最基本的功能是信息的传播,文字与其他设计元素相结合后,能更好地表达设计主题和构想,还能起到美化商品、宣传商品的作用。     

Handling the effect of non-response in graphical models for longitudinal data

In this paper we investigated the use of attrition weights to cope with non-response when selecting graphical chain models for longitudinal data. We proposed a parametric bootstrap approach to account for the extra variability introduced by the estimation of the weights and compared this with results using standard test procedures.     

Should commodity tax rates be uniform across regions in a heterogeneous country? Evidence from India

With countries increasingly adopting the Goods and Services Tax (GST) as their system of commodity taxes replacing the myriad of sales, excise and other form of indirect taxes, there is a move towards the two features that characterize the GST: uniform tax rates across items and identical tax rates across regions. When India introduced the GST in 2017, it followed several other countries in departing from the first feature but in keeping with universal practice embraced the second feature. The chief motivation of this paper is to subject this latter feature to critical scrutiny. The study examines the four GST rates in India by comparing them with counterfactual evidence based on preference based optimal commodity tax rates estimated by taking into account regional diversity in prices and spending. The benchmarking suggests that the current top GST rates (12%, 16% and 28%) are much higher than can be justified by the optimal rates. The Indian evidence is also in favor of departing from the universal practice in GST of adopting a uniform tax across items. The paper makes a methodological contribution by proposing a procedure for calculating spatial prices that can be applied to a wide basket of items. The study provides evidence on the redistributive potential of indirect taxation by showing the progressive nature of the optimal commodity taxes. The latter result is of particular significance in developing countries where indirect taxes raise the greater share of revenue and provide an important policy tool for tackling increasing inequality. The study concludes with a list of policy lessons as the country seeks to make further changes to its GST. While there is a significant literature on harmonization of indirect taxes across countries that belong to a single economic grouping such as the EU, there is no such literature between regions within a large heterogeneous country. The present study on tax harmonization between the states in India attempts to fill this gap.