采取网络型的政府市场供给模式应对房价问题

面对不断飙升的房价,从理论界到政策层面对其原因都有不同的解读,但从实践结果来看对房价的治理并不理想。本文在综合分析理论研究与国家调控政策的基础上,认为创新措施采取网络型的政府市场供给模式是解决房价过快上涨的有效途径。文章着重对这一模式进行了分析,并认为此举对缓解供需矛盾、解决市场的信息不对称、市场操控、改变预期、稳定房价等都有非常重要的作用。     

The adequacy of asymptotic approximations in the near-integrated autoregressive model with dependent errors

We consider the normalized least squares estimator of the parameter in a nearly integrated first-order autoregressive model with dependent errors. In a first step we consider its asymptotic distribution as well as asymptotic expansion up to order O_p(T⁻¹). We derive a limiting moment generating function which enables us to calculate various distributional quantities by numerical integration. A simulation study is performed to assess the adequacy of the asymptotic distribution when the errors are correlated. We focus our attention on two leading cases: MA(1) errors and AR(1) errors. The asymptotic approximations are shown to be inadequate as the MA root gets close to −1 and as the AR root approaches either −1 or 1. Our theoretical analysis helps to explain and understand the simulation results of Schwert (1989) and DeJong, Nankervis, Savin, and Whiteman (1992) concerning the size and power of Phillips and Perron's (1988) unit root test. A companion paper, Nabeya and Perron (1994), presents alternative asymptotic frameworks in the cases where the usual asymptotic distribution fails to provide an adequate approximation to the finite-sample distribution.     

国内外企业技术创新策略的博弈分析

入世后我国企业面临着国外企业日益加强的竞争压力，技术创新成为企业的重要选择。本文从技术创新成本的角度，建立了国内企业与国外企业技术创新竞争的静态博弈模型，根据模型，当国外企业以规模扩张为竞争目标时，我国企业只能选择渐进式的技术创新战略。     

Contemporary Extensions of the Rasch Model

This paper will introduce, discuss and illustrate two contemporary extensions of theRasch model: the one parameter logistic model (Verhelst and Glas, 1995) and theMultidimensional Rasch model (Hoijtink et al., 1999). Using data with respect tothe measurement of schizotypy (Vollema and Hoijtink, 2000) the most importantfeatures of both models will be illustrated. For the one parameter logistic modelthese include: a (discrete) discrimination parameter for each item; a test for itembias; and, estimation of the location of a person on the (latent) trait that is beingmeasured. For the multidimensional Rasch model these include: specification ofthe model; and, model selection. All analyses presented in this paper can be executedusing either OPLM (Verhelst et al., 1995), TESTFACT (Wilson et al.,1984) or ConQuest (Wu et al., 1998). At the end of the paper some features ofmodels and software that have not been discussed will be summarized.     

CEV模型的单位根检验研究

CEV模型（Constant Elasticity of Variance Model）作为常用的利率模型，在实证分析中得到了广泛运用，但是其单位根检验一直被忽略或者被默认可以使用迪基一富勒检验。本文首次运用Box—Cox变换的技巧，针对CEV模型的单位根检验问题，找到了合适的统计量并且证明其渐进分布存在，然后通过蒙特卡罗方法求出了该统计量的分布表。得到了在大样本的情形下可以沿用迪基一富勒检验，但在小样本的情形下与迪基一富勒检验有所偏差的结论。     

离散选择模型的基本原理及其发展演进评介

离散选择模型的研究真正兴起于19世纪50年代末，属于微观计量经济学的范畴。该模型能够对个体和家庭行为进行经验性的统计分析，因而在经济学和其他社会科学中得到广泛的应用。本文从离散选择模型的基本性质及效用最大化的理论背景出发，指出logit模型虽然使用的是最早并且最为广泛的离散选择模型，但是其存在着三大局限性：不能表示随机口味的变化、暗含成比例的替代形式和不能处理不可观测因素在不同期间相关的情形。GEV（含嵌套logit）、probit和混合logit模型等其他的离散选择模型，很大程度上都是为了避免这些限制而产生并发展起来的。     

应该用哪一个模型来描述中国货币市场利率的动态变化

本文论证了双曲模型是描述中国货币市场利率动态变化的最佳单因子利率模型。由极大似然估计可以得到单因子利率模型的边际密度函数。双曲模型的边际密度和非参数估计得到的边际密度函数拟合较好，其表现远远优于几个常见的利率模型（CIR、CKLS和AG模型）。与较一般的Ait-Sahalia模型相比差别很小，但参数形式得到简化，似然比检验也支持这一点。双曲模型在刻画利率的均值回复特征方面还克服了AG模型的不足。     

Forecasting economic time series using flexible versus fixed specification and linear versus nonlinear econometric models

Nine macroeconomic variables are forecast in a real-time scenario using a variety of flexible specification, fixed specification, linear, and nonlinear econometric models. All models are allowed to evolve through time, and our analysis focuses on model selection and performance. In the context of real-time forecasts, flexible specification models (including linear autoregressive models with exogenous variables and nonlinear artificial neural networks) appear to offer a useful and viable alternative to less flexible fixed specification linear models for a subset of the economic variables which we examine, particularly at forecast horizons greater than 1-step ahead. We speculate that one reason for this result is that the economy is evolving (rather slowly) over time. This feature cannot easily be captured by fixed specification linear models, however, and manifests itself in the form of evolving coefficient estimates. We also provide additional evidence supporting the claim that models which ‘win’ based on one model selection criterion (say a squared error measure) do not necessarily win when an alternative selection criterion is used (say a confusion rate measure), thus highlighting the importance of the particular cost function which is used by forecasters and ‘end-users’ to evaluate their models. A wide variety of different model selection criteria and statistical tests are used to illustrate our findings.     

在驱力均衡中国际人力资源战略发展实证研究——以上海地区跨国公司为例

本文透过文献探讨与集群分析的实证研究,划分上海地区跨国公司国际人力资源战略可分成“放 任无主人力资源战略”、“总部操控人力资源战略”、“地区自治人力资源战略”、以及“收放兼顾人力资源战略” 四种类型,并在此基础上建议跨国公司未来上朝向本土化的国际人力资源战略发展方向。     

中国经济增长空间相关性研究——基于"长三角"与"珠三角"的实证

本文建立了两套回归模型:无空间相关变量的单向和双向固定效应模型;有空间相关变量的单向和双向固定效应模型。对比分析后得出的结论有:"长三角"和"珠三角"区域内部的确存在经济增长的空间相关性,"珠三角"区域内部经济增长的空间相关性略大于"长三角"区域,但两者在统计上并没有显著的差别;两个地区都存在经济增长的β收敛,但"珠三角"地区呈现出更强的收敛性;对于影响"长三角"和"珠三角"经济增长的因素,有些相同和不同点值得关注。