我国旅游扶贫战略的思考

论文以旅游扶贫战略为切口,论述了旅游扶贫战略的可行性,并对我国目前采用的几种旅游扶贫模式加以分析研究,在此基础上指出旅游扶贫战略在实践中存在的问题,并根据这些问题制定出旅游扶贫战略的发展对策。     

Supplier‐Switching Inertia and Competitive Asymmetry: A Demand‐Side Perspective*

Building on strategic management, operations strategy, and supplier management literatures, this article presents a framework for supplier selection from the demand‐side perspective. We highlight the role of a purchasing firm's switching inertia in the supplier‐selection process and demonstrate the usefulness of our framework for the industrial automation industry. Empirical data for this study was collected from 171 corporate and plant‐level executives in pharmaceutical, chemical, and paper‐and‐pulp manufacturing industries in the United States. A series of Web‐based individually customized discrete choice experiments asked the respondents to either switch to the new supplier or stay with the existing supplier. Based on the results of these experiments, we demonstrate the existence of switching inertia in the supplier‐selection process and discuss the managerial implications for incumbent and challenger supplier firms.     

多阶模型在地区消费差异研究中的应用

 当组间差异显著时，应该运用多阶模型纳入更高阶的场景变量进行分析。对2007年广东省11市7县、区的1600个家庭的消费数据研究表明，不同城市之间居民的消费水平、边际消费倾向都存在显著差异。文章引入微观层面的家庭人均可支配收入（PDI）和是否拥有住房（HOUSE）虚拟变量来解释微观层面的家庭消费差异；引入宏观层面的地区人均可支配收入（GPDI）和是否为发达地区（D）虚拟变量作为场景变量解释家庭消费跨地区的差异。实证结果表明，微观层面变量对家庭消费差异（组内差异）的解释程度达48％以上，两个场景变量对城镇居民消费跨地区差异（组间差异）的解释程度达99％以上。     

基于周内多重分形波动率的基金投资风格漂移风险测度研究

基金发生投资风格漂移是把双刃剑，在获得短期超额收益时，也隐藏着巨大的风格漂移风险。本文首先以我国79只开放式股票型基金为样本，在量化投资风格漂移的基础上，分析发现其收益序列存在多重分形特征，据此构建周内多重分形波动率测度来刻画投资风格漂移收益的复杂波动特征，并与传统的GARCH族波动率计量模型的测度能力进行比较分析，实证结果发现本文构建的周内多重分形波动率测度更加精确，能更好刻画序列的复杂波动特征；然后，进一步构建MFVW VaR模型对基金投资风格漂移风险进行量化测度，发现该模型比传统的参数与非参数VaR模型能更好地对风格漂移风险进行有效测度，基金普遍存在较大的风格漂移风险；最后，对我国开放式股票型基金的产品创新策略与投资风格漂移监管策略进行了一些有益探讨。     

An Entropy‐Based Methodology for Valuation of Demand Uncertainty Reduction

We propose a distribution‐free entropy‐based methodology to calculate the expected value of an uncertainty reduction effort and present our results within the context of reducing demand uncertainty. In contrast to existing techniques, the methodology does not require a priori assumptions regarding the underlying demand distribution, does not require sampled observations to be the mechanism by which uncertainty is reduced, and provides an expectation of information value as opposed to an upper bound. In our methodology, a decision maker uses his existing knowledge combined with the maximum entropy principle to model both his present and potential future states of uncertainty as probability densities over all possible demand distributions. Modeling uncertainty in this way provides for a theoretically justified and intuitively satisfying method of valuing an uncertainty reduction effort without knowing the information to be revealed. We demonstrate the methodology's use in three different settings: (i) a newsvendor valuing knowledge of expected demand, (ii) a short life cycle product supply manager considering the adoption of a quick response strategy, and (iii) a revenue manager making a pricing decision with limited knowledge of the market potential for his product.     

A class of log-linear models with constrained marginal distributions

Summary In the log-linear model for bivariate probability functions the conditional and joint probabilities have a simple form. This property make the log-linear parametrization useful when modeling these probabilities is the focus of the investigation. On the contrary, in the log-linear representation of bivariate probability functions, the marginal probabilities have a complex form. So the log-linear models are not useful when the marginal probabilities are of particular interest. In this paper the previous statements are discussed and a model obtained from the log-linear one by imposing suitable constraints on the marginal probabilities is introduced. This work was supported by a M.U.R.S.T. grant.     

Forecasting a class of doubly stochastic Poisson processes

Received: July 21, 2000; revised version: April 24, 2001     

党员干部要努力成为"三个模范"

党的十六大报告中指出 ,党员干部要带头学习和实践“三个代表”重要思想 ,成为“三个模范” ,这是对当代共产党人提出的新要求 ,具有鲜明的时代特征。党员干部要提高对这一要求的思想认识 ,并且要努力身体力行     

Modelling Trends and Inequality in Small Area Mortality

This paper considers the modelling of mortality rates classified by age, time, and small area with a view to developing life table parameters relevant to assessing trends in inequalities in life chances. In particular, using a fully Bayes perspective, one may assess the stochastic variation in small area life table parameters, such as life expectancies, and also formally assess whether trends in indices of inequality in mortality are significant. Modelling questions include choice between random walk priors for age and time effects as against non-linear regression functions, questions of identifiability when several random effects are present in the death rates model, and the choice of model when both within and out-of-sample performance may be important. A case study application involves 44 small areas in North East London and mortality in five sub-periods (1986-88, 1989-91, 1992-94, 1995-97, 1998-2000) between 1986 and 2000, with the final period used for assessing out-of-sample performance.