长江三角洲区域新一轮经济发展前瞻

中国区域合作的发展正呈现出从“极化发展”向“泛化发展”的新态势,在这一背景下,长三角地区的区域合作也表现出一些新的特点。特别是国家关于《进一步推进长江三角洲地区改革开放和经济社会发展的指导意见》的提出,更为长三角地区的发展提供了新的发展契机和方向。研究《指导意见》,有助于从宏观上把脉长三角地区发展的重点及难点,并为珠三角、京津冀等城市群的发展提供借鉴。     

城市老年人对居家养老服务提供主体的选择及影响因素——基于福利多元主义视角的研究

居家养老是我国社会化养老服务的基础,诞生于西方发达国家的福利多元主义为我国国家主导型社会福利政策和居家养老服务的发展提供了理论资源。当前我国城市地区的居家养老服务主要依靠政府推动,市场化机制开始建立,老年群体对政府、社区依赖较高,对市场化服务供给主体的认可度仍有较大提升空间。加快发展居家养老服务,满足不同社会人口和经济特征老年人的多样化需求是一项社会系统工程。在创建多元化服务格局的过程中,需要政府、企业、社区、社会组织、志愿者、家庭和个人等各方参与主体明确权责,分工协作,扩大有效需求,统筹地区协调发展,凝聚推动供需两旺良性发展的合力。     

Retrospective change detection in categorical time series

The aim of this paper is to propose methods of detecting change in the coefficients of a multinomial logistic regression model for categorical time series offline. The alternatives to the null hypothesis of stationarity can be either the hypothesis that it is not true, or that there is a temporary change in the sequence. We use the efficient score vector of the partial likelihood function. This has several advantages. First, the alternative value of the parameter does not have to be estimated; hence, we have a procedure that has a simple structure with only one parameter estimation using all available observations. This is in contrast with the generalized likelihood ratio-based change point tests. The efficient score vector is used in various ways. As a vector, its components correspond to the different components of the multinomial logistic regression model’s parameter vector. Using its quadratic form a test can be defined, where the presence of a change in any or all parameters is tested for. If there are too many parameters one can test for any subset while treating the rest as nuisance parameters. Our motivating example is a DNA sequence of four categories, and our test result shows that in the published data the distribution of the four categories is not stationary.     

The Generalized Conditional Autoregressive Wishart Model for Multivariate Realized Volatility

It is well known that in finance variances and covariances of asset returns move together over time. Recently, much interest has been aroused by an approach involving the use of the realized covariance (RCOV) matrix constructed from high-frequency returns as the ex-post realization of the covariance matrix of low-frequency returns. For the analysis of dynamics of RCOV matrices, we propose the generalized conditional autoregressive Wishart (GCAW) model. Both the noncentrality matrix and scale matrix of the Wishart distribution are driven by the lagged values of RCOV matrices, and represent two different sources of dynamics, respectively. The GCAW is a generalization of the existing models, and accounts for symmetry and positive definiteness of RCOV matrices without imposing any parametric restriction. Some important properties such as conditional moments, unconditional moments, and stationarity are discussed. Empirical examples including sequences of daily RCOV matrices from the New York Stock Exchange illustrate that our model outperforms the existing models in terms of model fitting and forecasting.     

Penalised spline estimation for generalised partially linear single-index models

Generalised linear models are frequently used in modeling the relationship of the response variable from the general exponential family with a set of predictor variables, where a linear combination of predictors is linked to the mean of the response variable. We propose a penalised spline (P-spline) estimation for generalised partially linear single-index models, which extend the generalised linear models to include nonlinear effect for some predictors. The proposed models can allow flexible dependence on some predictors while overcome the “curse of dimensionality”. We investigate the P-spline profile likelihood estimation using the readily available R package mgcv, leading to straightforward computation. Simulation studies are considered under various link functions. In addition, we examine different choices of smoothing parameters. Simulation results and real data applications show effectiveness of the proposed approach. Finally, some large sample properties are established.     

中国出口垂直专业化的重新评估

文章借鉴了全球价值链分解模型,运用WIOD数据库中的世界投入产出表,对中国1995-2011年共17年的出口垂直专业化进行了重新评估.新的计算结果显示:(1)中国出口垂直专业化指数在2005年出现了下降趋势;美日欧等主要经济体为中国出口提供的中间品的比重出现下降,而新兴经济体的这一比重则上升较快;(2)中国垂直专业化结构发生了显著变化,最终品出口中的国外增加值比重不断下降,重复计算中的国外增加值比重则迅速扩大;(3)中国参与的垂直专业化分工仍然主要集中于技术和资本密集型的产业,但是各产业的垂直专业化指数在2005年前后也都出现了下降趋势,说明了中国产业结构和贸易结构呈现出优化的态势.     

A Bayesian sequential design with binary outcome

Several researchers have proposed solutions to control type I error rate in sequential designs. The use of Bayesian sequential design becomes more common; however, these designs are subject to inflation of the type I error rate. We propose a Bayesian sequential design for binary outcome using an alpha‐spending function to control the overall type I error rate. Algorithms are presented for calculating critical values and power for the proposed designs. We also propose a new stopping rule for futility. Sensitivity analysis is implemented for assessing the effects of varying the parameters of the prior distribution and maximum total sample size on critical values. Alpha‐spending functions are compared using power and actual sample size through simulations. Further simulations show that, when total sample size is fixed, the proposed design has greater power than the traditional Bayesian sequential design, which sets equal stopping bounds at all interim analyses. We also find that the proposed design with the new stopping for futility rule results in greater power and can stop earlier with a smaller actual sample size, compared with the traditional stopping rule for futility when all other conditions are held constant. Finally, we apply the proposed method to a real data set and compare the results with traditional designs.     

A note on budget constraints and outside options in common agency

Bernheim and Whinston (Q J Econ 101:1–31, 1986) show that, in a common agency problem without budget constraints, the set of Nash equilibria with truthful strategies (TNE), the set of coalition-proof Nash equilibria (CPNE), and the principal-optimal core of the underlying coalitional game are non-empty and all equivalent in payoff space. We show that, with budget constraints, none of Bernheim and Whinston’s (Q J Econ 101:1–31, 1986) results hold: (i) a CPNE may not exist, (ii) a TNE may not exist even when a CPNE exists, (iii) a TNE may not be a CPNE, and (iv) both TNE and CPNE payoffs are core allocations but are not necessarily principal-optimal. However, when principals have outside options but no budget constraints, (i), and (iii) continue to hold but not for (ii) and (iv). In particular, a TNE always exists but the core may be empty.     

Disequilibrium multi-dividing ontology learning algorithm

As an effective tool for data storage, processing, and computing, ontology has been used in many fields of computer science and information technology. By means of its powerful performance on semantic query and knowledge extraction, domain ontology has been built on various disciplines such as biology, pharmaceutics, geography, chemistry, etc. and been smoothly employed for their engineering applications. In these ontology applications, we aim to get an optimal ontology function which maps each ontology to a real number and then determine the similarity between concepts by the distance of their corresponding real numbers. In former ontology learning approaches, all the instances in the training sample have equal status in the learning process. In this article, we present the disequilibrium multi-dividing ontology algorithm in which the important ontology data will be highlighted during the learning, and the relevant ontology data tend to be eliminated. Four experiments are designed to test the serviceability of our disequilibrium multi-dividing algorithm from angles of ontology similarity measuring and ontology mapping construction.     

基于化学反应算法的鲜活农产品配送路径优化

文章通过引入时间价格因子考虑在鲜活农产品配送过程的损耗并结合运输成本和惩罚成本构建数学模型.从实际的运用环境出发,考虑到未在期望获得时间内达到运输地点的成本消耗,并且随着时间的推移,鲜活农产品本身也有成本损耗构建目标函数.根据该模型的特点设计化学反应的最小单元分子结构和算法步骤.运用化学反应算法可以很好地解决模型算法过早收敛于局部最优问题.通过实例验证了模型和算法的有效性和科学性.