论民营经济发展中的制约因素与改善对策

民营经济是我国社会主义市场经济体制中的重要组成部分,但现在它的发展受到多方面的制约。据此,对这些制约因素进行了分析,并提出了改善民营经济发展的一些对策。     

高技术企业经营者财务监控环境的多级可拓综合评价

随着全球高科技企业的迅猛发展,高科技企业已成为重要的经济增长点。由于高技术企业在技术、运作模式等方面的特殊性,应用传统的财务监控模式对高科技企业经营者监控的效果并不理想。根据高技术企业的特征,其财务监控系统应由环境系统、支撑主体系统和运行系统构成。选择有代表性的指标建立高技术企业环境系统的评价指标体系,采用层次分析法确定指标的权重,并以可拓学的多级物元作为基本概念,构建环境系统评价模型,可以为高技术企业财务监控环境系统评价提供可行的方法。实证结果表明,这一模型对高技术企业财务监控的环境系统有较好的评价效果。     

A Multilevel Analysis of Child Care and Women's Fertility Decisions in Western Germany

The availability of public day care is often assumed to be crucial to the compatibility of childrearing and women's employment. This article takes a multilevel perspective in investigating the role of child care in childbearing decisions in western Germany. Using information on the local supply of public day care and data from the German Socio‐Economic Panel, we estimated first and second birth risks from the 1980s and 1990s. We found that access to informal care arrangements increases the probability of entering parenthood, but we did not find any statistically significant effect of the public day care provision on fertility. This result points to shortcomings in the institutional setup of the German day care (and welfare) regime and to potentially relevant unobserved dimensions of child care.     

Tests for a simple tree order restriction with application to dose–response studies

Summary.  We propose 'Dunnett-type' test procedures to test for simple tree order restrictions on the means of p independent normal populations. The new tests are based on the estimation procedures that were introduced by Hwang and Peddada and later by Dunbar, Conaway and Peddada. The procedures proposed are also extended to test for 'two-sided' simple tree order restrictions. For non-normal data, nonparametric versions based on ranked data are also suggested. Using computer simulations, we compare the proposed test procedures with some existing test procedures in terms of size and power. Our simulation study suggests that the procedures compete well with the existing procedures for both one-sided and two-sided simple tree alternatives. In some instances, especially in the case of two-sided alternatives or for non-normally distributed data, the gains in power due to the procedures proposed can be substantial.     

A micro analysis of the macro differences in refusal risk among metropolitan areas. The case of the Italian multipurpose survey

Although still modest, non response rates in multipurpose household surveys have recently increased, especially in some metropolitan areas. Previous analyses have shown that refusal risk depends on the interviewers' characteristics. The aim of this paper is to explain the difference in refusal risk among metropolitan areas by analysing the strategies adopted in the recruitment of interviewers through a multilevel approach. The Annual Survey on Living conditions is a PAPI survey of the "Multipurpose" integrated system of social surveys and it represents our data base. For non responding household, data on non response by reason, municipality and characteristics of the interviewer are available. The results highlight that those cities recruiting interviewers mainly among young students have a higher refusal risk. These results are particularly important as they indicate that recruitment strategies may have a substantial impact on non sampling errors. Acknowledgements An earlier version of this article was presented at the International Conference on Improving Survey, University of Copenhagen, Denmark, August 25-28, 2002. We would like to thank the participants to the presentation for their useful comments and suggestions. Opinions expressed are those of the authors and do not necessarily represent the official position of any of the institutions they work for.     

一种基于实现站点系统完整度的数据库多级查询方法

提出了站点完整度概念,并实现了其在站点设计中的应用;设计了在广域网环境下的基于实现站点系统完整度的数据库查询模型,同时给出了在该模型下将模糊查询与超媒体检索相结合的实现方法．     

Two kinds of restricted modified estimators in linear regression model

In this paper, we introduce two kinds of new restricted estimators called restricted modified Liu estimator and restricted modified ridge estimator based on prior information for the vector of parameters in a linear regression model with linear restrictions. Furthermore, the performance of the proposed estimators in mean squares error matrix sense is derived and compared. Finally, a numerical example and a Monte Carlo simulation are given to illustrate some of the theoretical results.     

Multilevel modelling of survey data: impact of the two-level weights used in the pseudolikelihood

Approaches that use the pseudolikelihood to perform multilevel modelling on survey data have been presented in the literature. To avoid biased estimates due to unequal selection probabilities, conditional weights can be introduced at each level. Less-biased estimators can also be obtained in a two-level linear model if the level-1 weights are scaled. In this paper, we studied several level-2 weights that can be introduced into the pseudolikelihood when the sampling design and the hierarchical structure of the multilevel model do not match. Two-level and three-level models were studied. The present work was motivated by a study that aims to estimate the contributions of lead sources to polluting the interior floor dust of the rooms within dwellings. We performed a simulation study using the real data collected from a French survey to achieve our objective. We conclude that it is preferable to use unweighted analyses or, at the most, to use conditional level-2 weights in a two-level or a three-level model. We state some warnings and make some recommendations.     

Performance analysis of the preliminary test estimator with series of stochastic restrictions

In this paper, the problem of estimation of the regression coefficients in a multiple regression model is considered under the multicollinearity situation when there are series of stochastic linear restrictions available on the regression parameter vector. We have considered the preliminary test ridge regression estimators (PTRREs) based on the Wald, likelihood ratio, and lagrangian multiplier tests. Tables for the maximum and minimum guaranteed efficiency of the PTRREs are obtained, which allow us to determine the optimum choice of the level of significance corresponding to the optimum estimator. Some numerical results support the findings.     

A review of the effectiveness of empowering leadership

Based on a review of empirical literature on empowering leadership, given incongruent and mixed results, the current work suggests reconsidering the effectiveness of empowering leadership. We propose a framework for examining the effectiveness of empowering leadership that considers: 1) feasibility of non-linear main effects of empowering leadership on work-related outcomes, 2) possibility of reverse causation between empowering leadership and work-related outcomes, 3) potential contradictory mediating mechanisms through which empowering leadership influences work-related outcomes, 4) consideration of boundary conditions which could alter the relationships between empowering leadership and work-related outcomes, and 5) consideration of levels-of-analysis and multilevel issues in empowering leadership. Our framework considers the multifaceted nature of empowering leadership and offers a guiding tool for advancing future research in this area.