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.     

Party alternation,divided government,and fiscal performance within US States

The literature on US state government fiscal performance has examined the role of institutional factors such as budget rules and divided government, but has largely ignored the impact of party alternation. This paper primarily focuses on whether party alternation in the governor’s office affects fiscal performance. Our hypothesis is that frequent party changes create a political environment that impacts fiscal performance. To further assess the impact of party alternation on fiscal performance, we consider our primary hypothesis in conjunction with the degree of division that exists between the governor’s office and the legislature. Using panel data from 37 states between 1971 and 2000 we test the hypothesis that frequent party alternation can be expected to affect fiscal performance and find strong support for the hypothesis. An earlier version of this paper was presented at the 2005 Public Choice Society Meetings. The authors would like to thank the conference participants, William Shughart, Charles Register, Jocelyn Evans, John D. Jackson, Amihai Glazer, and two anonymous referees for their comments. We would also like to thank Craig R. Stiller for his help in the collection of data. Any remaining errors remain the responsibility of the authors.     

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.     

城市空间发展哲学思辩

通过对十多个城市空间发展的个案分析 ,作者指出 ,在城市空间拓展过程中 ,通过规划调控、行政区划调整等手段 ,可以使城市劣势空间变优势空间 ,使分割空间变整体空间 ,平淡空间变特色空间 ,变限制空间为超越限制空间     

分形理论在货运量预测中的应用探讨

在已有研究的基础上，提出了一种新的分形预测模型——等长度递补变维分形模型。首先阐述了等长度递补变维分形模型的基本原理；然后利用该模型对1990年～2004年我国货运量进行了预测，并利用后验差方法分析了模型的精度；最后利用模型预测了2005年～2010年我国货运量及其构成（铁路、公路和水运各自所占比重）.     

货币政策和银行风险承担：一种非线性关系

宽松的货币政策会通过估值、收入和现金流机制,追逐收益机制以及中央银行沟通和反应机制等渠道增加银行风险承担,通过风险转移机制降低银行风险承担,从而导致货币政策与银行风险承担之间可能存在复杂的非线性关系。本文使用面板阈值模型,基于我国银行业数据研究了货币政策对银行风险承担的影响,发现我国货币政策对银行风险承担的影响存在门限效应,即货币政策对银行风险承担的影响取决于货币政策基准利率偏离泰勒规则利率的程度。当这种偏离小于门限值时,宽松货币政策会增加银行风险承担;当这种偏离大于门限值时,宽松货币政策会降低银行风险承担。本文研究对更好地理解我国货币政策对银行风险承担及金融稳定的影响有一定参考意义。