农村劳动力转移与山西现代农业驱动模式研究

运用协整回归和误差修正模型,以山西省为例,实证分析农村劳动力转移对现代农业的影响。结果表明,1996²011年,农村劳动生产率、财政支农资金比例和城镇化水平的对数与农村转移劳动力比例之间存在协整关系,且误差修正机制存在;β系数进一步表明农村转移劳动力对农业现代化的影响作用最大,并且前者是后者的Granger因。证实了现代农业驱动处于人口转移驱动型阶段,尚未进入城镇化驱动阶段。据此提出建议:继续积极鼓励和引导农村劳动力有序、健康转移;提高财政支农比例,提升财政支农资金运用效率;对城镇化模式进行科学动态调整,纠正城镇化偏差。     

积极推进社区矫正立法,健全完善社区矫正执行体系

十八届三中全会《中共中央关于全面深化改革若干重大问题的决定》决定：“废止劳动教养制度,完善对违法犯罪行为的矫治和矫正法律,健全社区矫正制度”。我国实践十多年的社区矫正工作进入发展的快车道,积极推进社区矫正立法,科学合理设定社区矫正机关,规范程序,健全完善社区矫正执行体系,提高教育矫正的针对性和实效性,实现社区矫正目的。     

作为国家正式制度的信访制度

为什么信访制度在中国延续了几千年?本文研究发现,信访制度不是老百姓建立的,而是中央政府建立的;不是非正式制度,而是国家正式制度,是中国政治体制的重要组成部分,是管理国家的日常形式;信访制度既是为百姓服务的,更是为国家服务的,是为了弥补体制缺陷和国家长治久安而建立起来的。     

我国货币需求模型实证分析研究

从西方货币需求理论出发,根据我国的实际情况,并考察货币需求M1、M2和股票价格指数、GDP、利率、消费价格指数以及外汇储备之间的实际关系,可以建立我国货币需求的长期均衡方程和误差修正模型.     

Bias correction and improved residuals for non-exponential family nonlinear models

In this paper we derive general formulae for the biases to order n ^?1 of the parameter estimates in a general class of nonlinear regression models, where n is the sample size. The formulae are related to those of Cordeiro and McCullagh (1991) and Paula (1992) and may be viewed as extensions of their results, Correction factors are derived for the score and deviance component residuals in these models. The practical use of such corrections is illustrated for the log-gamma model.     

Robustness and Corrections for Sample Size Adaptation Strategies Based on Effect Size Estimation

A study on the robustness of the adaptation of the sample size for a phase III trial on the basis of existing phase II data is presented—when phase III is lower than phase II effect size. A criterion of clinical relevance for phase II results is applied in order to launch phase III, where data from phase II cannot be included in statistical analysis. The adaptation consists in adopting the conservative approach to sample size estimation, which takes into account the variability of phase II data. Some conservative sample size estimation strategies, Bayesian and frequentist, are compared with the calibrated optimal γ conservative strategy (viz. COS) which is the best performer when phase II and phase III effect sizes are equal. The Overall Power (OP) of these strategies and the mean square error (MSE) of their sample size estimators are computed under different scenarios, in the presence of the structural bias due to lower phase III effect size, for evaluating the robustness of the strategies. When the structural bias is quite small (i.e., the ratio of phase III to phase II effect size is greater than 0.8), and when some operating conditions for applying sample size estimation hold, COS can still provide acceptable results for planning phase III trials, even if in bias absence the OP was higher.

Main results concern the introduction of a correction, which affects just sample size estimates and not launch probabilities, for balancing the structural bias. In particular, the correction is based on a postulation of the structural bias; hence, it is more intuitive and easier to use than those based on the modification of Type I or/and Type II errors. A comparison of corrected conservative sample size estimation strategies is performed in the presence of a quite small bias. When the postulated correction is right, COS provides good OP and the lowest MSE. Moreover, the OPs of COS are even higher than those observed without bias, thanks to higher launch probability and a similar estimation performance. The structural bias can therefore be exploited for improving sample size estimation performances. When the postulated correction is smaller than necessary, COS is still the best performer, and it also works well. A higher than necessary correction should be avoided.     

The Appropriateness of Some Common Procedures for Testing the Equality of Two Independent Binomial Populations

For testing the equality of two independent binomial populations the Fisher exact test and the chi-squared test with Yates's continuity correction are often suggested for small and intermediate size samples. The use of these tests is inappropriate in that they are extremely conservative. In this article we demonstrate that, even for small samples, the uncorrected chi-squared test (i.e., the Pearson chi-squared test) and the two-independent-sample t test are robust in that their actual significance levels are usually close to or smaller than the nominal levels. We encourage the use of these latter two tests.     

A Comparison of Large-Sample Confidence Interval Methods for the Difference of Two Binomial Probabilities

A simulation study was done to compare seven confidence interval methods, based on the normal approximation, for the difference of two binomial probabilities. Cases considered included minimum expected cell sizes ranging from 2 to 15 and smallest group sizes (NMIN) ranging from 6 to 100. Our recommendation is to use a continuity correction of 1/(2 NMIN) combined with the use of (N ? 1) rather than N in the estimate of the standard error. For all of the cases considered with minimum expected cell size of at least 3, this method gave coverage probabilities close to or greater than the nominal 90% and 95%. The Yates method is also acceptable, but it is slightly more conservative. At the other extreme, the usual method (with no continuity correction) does not provide adequate coverage even at the larger sample sizes. For the 99% intervals, our recommended method and the Yates correction performed equally well and are reasonable for minimum expected cell sizes of at least 5. None of the methods performed consistently well for a minimum expected cell size of 2.