Panel LM unit root tests with level and trend shifts

This paper considers a Lagrange multiplier (LM) based panel unit root test that allows for heterogeneous structural breaks in both the intercepts and slopes of a series. We note that many popular time series variables are likely to exhibit changing means and/or trends over time. Given that the usual tests will depend on the nuisance parameters indicating the locations of the trend breaks, we adopt a transformation procedure that makes our new panel unit root tests invariant to the nuisance parameters. To illustrate the importance of the power gain provided by our test, we examine the convergence hypothesis using relative ratios of per capita health care expenditures in 20 OECD countries. Our results provide evidence that the convergence hypothesis is supported.     

Consumption and stock markets in Asian economies

This paper investigates the causal links between stock market performance and consumption for five Asian economies by applying the bound tests of Pesaran et al. and lag augmented VAR of Toda and Yamamoto . We find two‐way causal relationships between stock market performance and consumption in the cases of Hong Kong and Taiwan in the long run. The existence of such two‐way causal links indicates that stock market performance and consumption mutually affect each other, implying that the previous studies may have overestimated the wealth effect of the stock markets without taking account of the reverse causation from consumption to the stock markets. The short‐run effect of the stock market on consumption is more visible than the long‐run effect in most of the sample economies, suggesting that changes in consumption directly reflect stock market fluctuations.     

抽油机V带执行标准现状及有关问题探讨

阐述了国内外V带现行标准状况，指出通用V带标准应用于抽油机V带存在的问题。针对抽油机用V带寿命不足5000h的问题，提出制定符合中国油田实际的《抽油机用V带》新标准，并从五个方面提出了编写新标准的建议。     

Hypothesis tests using data envelopment analysis

A substantial body of recent work has opened the way to exploring the statistical properties of DEA estimators of production frontiers and related efficiency measures. The purpose of this paper is to survey several possibilities that have been pursued, and to present them in a unified framework. These include the development of statistics to test hypotheses about the characteristics of the production frontier, such as returns to scale, input substitutability, and model specification, and also about variation in efficiencies relative to the production frontier.     

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.     

当代艺术审美理想的迷失与重建

中国当代艺术审美理想的迷失从根子上说是有些中国作家和艺术家社会背叛的结果,从美学上说,不但是席勒当年所批判的恶劣倾向的沉渣泛起,而且消解了人对自己的尊严的捍卫和对自由的追求。中国当代艺术审美理想的重建就是要求中国作家和艺术家精神寻根,按照美的规律创造。     

加强地勘单位领导班子自身建设初探

文章认为,要建设一个优秀的地勘单位领导班子,应努力做好思想政治及组织建设工作,正确处理民主与集中、集体与个人、局部与全局等方面的关系。     

The Nested PIGLOG Model: An Application to U.S. Food Demand

A new demand system is introduced, the Nested PIGLOG model, nesting thirteen other demand systems including five that are also new. This new model and its nested special cases are applied to models of U.S. food demand that include food-at-home (FAH), food-away-from-home (FAFH), and alcoholic beverages. Although nested tests and out-of-sample forecasting performance favor generalizing models to a certain degree, statistically insignificant improvements to in-sample-fit and even poorer out-of-sample forecast accuracy undermine further generalizations. Based on a subset of preferred models, FAFH is found to be price and income elastic compared to FAH which is price and income inelastic.     

小学体育新课标目标统领下单元教学计划的研究

新的全日制义务教育《体育(1至6年级)课程标准,》对体育课提出了运动参与、运动技能、身体健康、心理健康和社会适应等五大领域的教学目标。文章通过实验,在对比中阐述了以新课程标准为教学目标,进行有针对性的教学设计和课堂实施,可使学生各方面的发展更符合新时期的要求的观点,并提出了单元教学计划设计的方法。     

Progressive stress accelerated life tests under finite mixture models

In this paper, progressive stress accelerated life tests are considered when the lifetime of a product under use condition follows a finite mixture of distributions. The experiment is performed when each of the components in the mixture follows a general class of distributions which includes, among others, the Weibull, compound Weibull, power function, Gompertz and compound Gompertz distributions. It is assumed that the scale parameter of each component satisfies the inverse power low, the progressive stress is directly proportional to time and the cumulative exposure model for the effect of changing stress holds. Based on type-I censoring, the maximum likelihood estimates (MLEs) of the parameters under consideration are obtained. A special attention is paid to a mixture of two Rayleigh components. Simulation results are carried out to study the precision of the MLEs and to obtain confidence intervals for the parameters involved.