On randomization, modeling and experimental design; a new example in an old discussion

Fisher and "Student" quarreled in the early days of statistics about the design of experiments, meant to measure the difference in yield between to breeds of corn. This discussion comes down to randomization versus model building. More than half a century has passed since, but the different views remain. In this paper the discussion is put in terms of artificial randomization and natural randomization, the latter being what remains after appropriate modeling. Also the Bayesian position is discussed. An example in terms of the old corn-breeding discussion is given, showing that a simple robust model may lead to inference and experimental design that outperforms the inference from randomized experiments by far. Finally similar possibilities are suggested in statistical auditing.     

The Significance of Credit Rationing on Real Investment Activity – A Test for the Significance of Capital-Market Imperfection in Japan

Does bank credit matter to the real investment finance of firms? If so, to what kind of firms does it matter, and why? Despite the progress of research in this field, there is still little empirical consensus on these problems. This paper contributes to the understanding of capital-market imperfection in Japan by answering these questions. I introduce new methods to test the significance of credit rationing and show that bank credit is indeed a very important determinant of real investment activity of small firms. The availability of long-term loans has particularly significant effects on the investment opportunities of small firms, although large firms with capital of more than 1 billion yen are free from credit rationing. JEL Classification Numbers: C51, E44, G21.     

统计推断中的Fuzzy信息

本文以一个正态总体均值的假设检验为例,说明统计推断中一般存在有 Fuzzy 信息,并揭示了 Fuzzy 信息的作用。首次指出了对统计推断结果进行Fuzzy 信息分析的必要性。     

Reduced-bias tail index estimation and the jackknife methodology

In the context of regularly varying tails, we first analyze a generalization of the classical Hill estimator of a positive tail index, with members that are not asymptotically more efficient than the original one. This has led us to propose alternative classical tail index estimators, that may perform asymptotically better than the Hill estimator. As the improvement is not really significant, we also propose generalized jackknife estimators based on any two members of these two classes. These generalized jackknife estimators are compared with the Hill estimator and other reduced-bias estimators available in the literature, asymptotically, and for finite samples, through the use of Monte Carlo simulation. The finite-sample behaviour of the new reduced-bias estimators is also illustrated through a practical example in the field of finance.     

试论城乡发展差距的统计监测

在传统经济向现代经济转变过程中城乡发展差距的出现有一定的必然性,但过大的城乡差距如果长期存在也会带来一系列严重的社会问题,因此必须加强对差距大小的监测分析.本文专题探讨了开展城乡发展差距统计监测的意义、城乡发展差距统计监测体系基本框架的构建、以及实施城乡发展差距统计监测的保障措施.     

最优污染水平的数学解析与模式

针对环境经济学中最优污染水平概念模糊的问题，运用几何解析与逻辑推演方法，分析最优污染水平定性模式的病症所在，导出最优污染水平的充分条件和必要条件，并进一步运用导数和微分学理论证明了该充分条件和必要条件的正确性，从而创建了新的最优污染水平的定量模式。     

基于WEB的银行统计信息系统安全策略研究

本文分析了国内外银行信息系统安全现状,通过基于WEB的银行统计信息系统的开发,给出一种在Web方式下根据银行管理安全性要求而制定相应系统安全性策略的方法,并开发了内嵌信息安全、保密机制、合理授权的统计信息系统,从而为整个系统的安全运作提供有效保证。     

论我国房地产市场预警系统的建立

建立房地产市场预警系统有助我们在恰当的时候采用正确的房地产宏观调控措施促进房地产市场健康发展。本文将房价收入比、房价租金比、租金收入比、房地产价格增长率与GDP增长率之比、商品房空置率5个指标作为房地产市场预警统计指标,并对它们的预警区间做出界定,然后根据每个指标的统计数据,确定警兆的警级,结合警兆的重要性进行加权综合,综合成一个指数,这样就可以用一组类似于交通信号灯的标志把当前的房地产市场状态直观地表达出来,用以判断房地产市场过热或衰退的程度,来制定房地产宏观调控的方向。     

A measure of regional influence with the analytic network process

The metropolitan region is commonly defined by a socio-spatial network of urban nodes that are linked in territory and function. Such a network is differentiated by size and dominance of the linked nodes, characterized by physical or virtual flows of a wide-ranging variety. The analytic network process (ANP) is a multi-criteria analytic method that measures the influence or dominance of the nodes in a network with feedback. We illustrate how ANP determines county rank as a measure of influence in a metropolitan statistical area (MSA) defined by its interrelated socio-economic and spatial elements qualitatively and quantitatively. We compare the ANP results to similar measures of regional influence in the literature.     

Mixture of MLP-experts for trend forecasting of time series: A case study of the Tehran stock exchange

A new method for forecasting the trend of time series, based on mixture of MLP experts, is presented. In this paper, three neural network combining methods and an Adaptive Network-Based Fuzzy Inference System (ANFIS) are applied to trend forecasting in the Tehran stock exchange. There are two experiments in this study. In experiment I, the time series data are the Kharg petrochemical company’s daily closing prices on the Tehran stock exchange. In this case study, which considers different schemes for forecasting the trend of the time series, the recognition rates are 75.97%, 77.13% and 81.64% for stacked generalization, modified stacked generalization and ANFIS, respectively. Using the mixture of MLP experts (ME) scheme, the recognition rate is strongly increased to 86.35%. A gain and loss analysis is also used, showing the relative forecasting success of the ME method with and without rejection criteria, compared to a simple buy and hold approach. In experiment II, the time series data are the daily closing prices of 37 companies on the Tehran stock exchange. This experiment is conducted to verify the results of experiment I and to show the efficiency of the ME method compared to stacked generalization, modified stacked generalization and ANFIS.