余价值的分配与账面剩余价值率

在价值转形过程中,由于剩余价值的均衡分配,从不同的利润率出发,可以得到同样的利润率,但并不影响剩余价值率,因为工作日、工人的必要劳动时间和剩余劳动时间在价值转形过程中都没有发生变化。本文提出“账面剩余价值率”的概念,来考察根据资本家的财务报表计算的“剩余价值率”。源于价值转形的“账面剩余价值率”就是“转形账面剩余价值率”;包含资本家在竞争过程中通过各种手段获得的（剩余）价值,由资本主义企业的财务报表中的（息税前）利润量直接计算的账面剩余价值率,就是“竞争账面剩余价值率”。由于剩余价值率是剩余劳动时间与必要劳动时间的比值,因此,可以首先确定所有生产工人的总劳动时间,然后再确定所有生产工人为自己生产的必要劳动时间,进而计算（真正的）总的剩余价值率。随着价值转形过程被垄断所破坏,不同部门的利润率差异被保留甚至扩大,一字曲线就变成了微笑曲线。     

中国区域经济增长对环境质量的影响——基于东、中、西部地区环境库兹涅茨曲线的实证研究

通过构建综合环境污染水平指标,运用1991--2009年省际面板数据,创新性地通过因子分析法,分析中国东、中、西部地区环境库兹涅茨曲线。结果表明：中国东、中、西部地区环境库兹涅茨曲线均呈“N型”,但地区之间正处于不同的阶段,东部地区的综合环境污染水平随经济增长呈下降趋势;中部和西部地区综合环境污染水平随经济增长呈上升趋势,造成这一差异的原因来自于规模效应、结构效应、技术效应、资源禀赋效应和环保规制效应。     

Bounding sample size projections for the area under a ROC curve

Studies of diagnostic tests are often designed with the goal of estimating the area under the receiver operating characteristic curve (AUC) because the AUC is a natural summary of a test's overall diagnostic ability. However, sample size projections dealing with AUCs are very sensitive to assumptions about the variance of the empirical AUC estimator, which depends on two correlation parameters. While these correlation parameters can be estimated from the available data, in practice it is hard to find reliable estimates before the study is conducted. Here we derive achievable bounds on the projected sample size that are free of these two correlation parameters. The lower bound is the smallest sample size that would yield the desired level of precision for some model, while the upper bound is the smallest sample size that would yield the desired level of precision for all models. These bounds are important reference points when designing a single or multi-arm study; they are the absolute minimum and maximum sample size that would ever be required. When the study design includes multiple readers or interpreters of the test, we derive bounds pertaining to the average reader AUC and the ‘pooled’ or overall AUC for the population of readers. These upper bounds for multireader studies are not too conservative when several readers are involved.     

Modeling a cross-sectional response variable with longitudinal predictors: an example of pulse pressure and pulse wave velocity

We wish to model pulse wave velocity (PWV) as a function of longitudinal measurements of pulse pressure (PP) at the same and prior visits at which the PWV is measured. A number of approaches are compared. First, we use the PP at the same visit as the PWV in a linear regression model. In addition, we use the average of all available PPs as the explanatory variable in a linear regression model. Next, a two-stage process is applied. The longitudinal PP is modeled using a linear mixed-effects model. This modeled PP is used in the regression model to describe PWV. An approach for using the longitudinal PP data is to obtain a measure of the cumulative burden, the area under the PP curve. This area under the curve is used as an explanatory variable to model PWV. Finally, a joint Bayesian model is constructed similar to the two-stage model.     

我国通货膨胀决定因素的计量分析

本文对我国总需求因素、货币因素和生产成本因素对通货膨胀的影响进行计量研究。通过测算菲利普斯曲线的动态变化,本文认为产出缺口对我国通货膨胀的影响呈现稳定下降的趋势,这说明总需求对我国通货膨胀的拉动效应在减小。本文选择了对通货膨胀具有重要影响的货币因素和产品购进价格因素,利用NBER方法分别计算合成指数,并将得到的合成指数与反映工资成本的指标共同引入扩展的菲利普斯曲线中,模型计算结果表明,货币因素和生产成本对物价具有显著的推动效应。因此,本文认为,在当前我国紧缩的货币政策背景下,产品购进价格尤其是工资成本的上升是通货膨胀率居高不下的决定性原因。     

Minimum hellinger distance estimation for normal models

A robust estimator introduced by Beran (1977a, 1977b), which is based on the minimum Hellinger distance between a projection model density and a nonparametric sample density, is studied empirically. An extensive simulation provides an estimate of the small sample distribution and supplies empirical evidence of the estimator performance for a normal location-scale model. While the performance of the minimum Hellinger distance estimator is seen to be competitive with the maximum likelihood estimator at the true model, its robustness to deviations from normality is shown to be competitive in this setting with that obtained from the M-estimator and the Cramér-von Mises minimum distance estimator. Beran also introduced a goodness-of-fit statisticH ₂, based on the minimized Hellinger distance between a member of a parametric family of densities and a nonparametric density estimate. We investigate the statistic H (the square root of H ₂) as a test for normality when both location and scale are unspecified. Empirically derived critical values are given which do not require extensive tables. The power of the statistic H compares favorably with four other widely used tests for normality.     

CONFIDENCE INTERVALS FOR THE DIFFERENCE BETWEEN TWO PARTIAL AUCS

As new diagnostic tests are developed and marketed, it is very important to be able to compare the accuracy of a given two continuous‐scale diagnostic tests. An effective method to evaluate the difference between the diagnostic accuracy of two tests is to compare partial areas under the receiver operating characteristic curves (AUCs). In this paper, we review existing parametric methods. Then, we propose a new semiparametric method and a new nonparametric method to investigate the difference between two partial AUCs. For the difference between two partial AUCs under each method, we derive a normal approximation, define an empirical log‐likelihood ratio, and show that the empirical log‐likelihood ratio follows a scaled chi‐square distribution. We construct five confidence intervals for the difference based on normal approximation, bootstrap, and empirical likelihood methods. Finally, extensive simulation studies are conducted to compare the finite‐sample performances of these intervals, and a real example is used as an application of our recommended intervals. The simulation results indicate that the proposed hybrid bootstrap and empirical likelihood intervals outperform other existing intervals in most cases.     

试用导数法判断曲线的对称性

利用函数的奇偶性和导数的有关概念,推导了几个用导数的方法判断函数图象对称性的结论,并通过实例验证了这些结论对判断一般曲线的对称性是方便可行的.     

金融深化与区域创新效率——基于跨国面板数据的分析

创新是引领发展的第一动力,是牵动经济社会发展全局的"牛鼻子",区域创新效率用创新的投入产出比衡量了一个地区的综合创新绩效,其影响因素存在多个方面。金融深化是衡量金融发展水平的重要指标。为研究各国金融深化与区域创新效率之间相互影响及其内在作用机制,作者首先借鉴多投入与多产出的DEA方法测算了80个国家的区域创新效率,然后使用Tobit模型对2011—2018年80个跨国面板数据进行实证分析。研究发现:金融深化与区域创新效率之间存在显著的"U"型曲线关系,即随着金融深化的提升,其对区域创新效率的影响将从"抑制"效应向"促进"效应转变。这是因为金融深化较低时,风险贷款和信用贷款发展滞后、风险投资渠道不完善以及金融结构和金融市场不健全导致多层次、立体化企业融资融券功能落后,从而抑制企业的创新效率。而金融深化较高时,风险投资渠道逐步完善、企业融资成本低、金融市场和金融结构完善,从而促进企业创新效率。研究还发现,各国经济水平的不同也会导致各国金融深化和区域创新效率有显著差异。作者将国家按照经济发展水平分为发达组和欠发达组,分组研究发现,金融深化对区域创新效率具有选择效应,即金融深化对欠发达国家创新效率具有"U"型曲线特征,而在发达组则不存在这种效应。原因在于:发达国家经济发展水平较高,金融结构和金融市场完善,风险投资渠道畅通无阻,金融深化提升区域创效率的影响不再呈现"抑制"效应。而在欠发达国家,经济发展水平较低,金融结构和金融市场发展水平正处于发展和完善的阶段。对于完善的金融市场和金融结构的部分,金融深化对区域创新效率的影响是"促进"效应,而对于不完善的部分,金融深化对区域创新效率的影响是"抑制"效应。为检验研究结果的稳健性,作者运用了滞后项检验、替代变量检验两种检验方法,检验结果具有稳健性,即随着金融深化的提升,其对区域创新效率的影响将从"抑制"效应向"促进"效应转变。因此,政府部门应该正确认识金融深化对区域创新效率的作用,完善创新体系,加强金融监管,防范化解金融风险,兼顾长期利益和短期利益,发挥金融深化对区域创新和经济增长的促进作用,推动金融体系更好适应新时代创新需求,以此来促进区域创新效率的提升。文章的研究结论对利用金融深化提高创新效率的发展中国家有启示和借鉴意义。     

毛涤混纺织物折皱回复性能的探讨

根据标准的折皱回复测试实验,提出分析毛涤混纺织物的折皱回复性能与混纺比关系的理论曲线.实践证明,曲线在一定的范围内对涤棉等混纺织物具有适用性.