我国粮食生产的环境技术效率测度

采用方向距离函数和Kernel密度估计方法,对1992—2012年中国29个省（市、区）的粮食生产环境技术效率进行了测度和分析,以考察城镇化和工业化加速时期中国各省份以及各粮食生产功能区粮食生产与资源环境的协调情况。研究结果表明：（1）全国及各粮食生产功能区粮食生产环境状况总体上呈现出逐渐恶化现象,其中,粮食主产区优于粮食主销区,粮食主销区优于粮食平衡区;（2）中国各省份粮食生产环境技术效率存在明显的非均衡性;（3）总体而言,我国粮食生产环境技术效率的地区差距在逐渐扩大,呈现出两级分布, 但是在各个粮食生产功能区形势有所不同。     

Empirical Likelihood for the Additive Hazards Model with Current Status Data

We investigate empirical likelihood for the additive hazards model with current status data. An empirical log-likelihood ratio for a vector or subvector of regression parameters is defined and its limiting distribution is shown to be a standard chi-squared distribution. The proposed inference procedure enables us to make empirical likelihood-based inference for the regression parameters. Finite sample performance of the proposed method is assessed in simulation studies to compare with that of a normal approximation method, it shows that the empirical likelihood method provides more accurate inference than the normal approximation method. A real data example is used for illustration.     

Estimation of Population Variance from Multi-ranker Ranked Set Sampling Designs

In this article, we develop an estimator for a population variance based on a multi-ranker ranked set sampling design. In a multi-ranker design, the units are ranked by more than one ranker allowing ties whenever the confidence level of the rankers is low. The ranking information of all rankers is then combined in a meaningful way to create a single measure. This measure is used to construct the sampling design and a new estimator for the population variance. The article investigates the bias and relative efficiency of the proposed variance estimator. It is shown that the new estimator performs as good as or better than its competitors in the literature.     

Conditional VAR and Expected Shortfall: A New Functional Approach

We estimate two well-known risk measures, the value-at-risk (VAR) and the expected shortfall, conditionally to a functional variable (i.e., a random variable valued in some semi(pseudo)-metric space). We use nonparametric kernel estimation for constructing estimators of these quantities, under general dependence conditions. Theoretical properties are stated whereas practical aspects are illustrated on simulated data: nonlinear functional and GARCH(1,1) models. Some ideas on bandwidth selection using bootstrap are introduced. Finally, an empirical example is given through data of the S&P 500 time series.     

On the Joint Estimation of Heterogeneous Technologies,Technical, and Allocative Inefficiency

In this article, we provide a semiparametric approach to the joint measurement of technical and allocative inefficiency in a way that the internal consistency of the specification of allocative errors in the objective function (e.g., cost function) and the derivative equations (e.g., share or input demand functions) is assured. We start from the Cobb–Douglas production and shadow cost system. We show that the shadow cost system has a closed-form likelihood function contrary to what was previously thought. In turn, we use the method of local maximum likelihood applied to a system of equations to obtain firm-specific parameter estimates (which reveal heterogeneity in production) as well as measures of technical and allocative inefficiency and its cost. We illustrate its practical application using data on U.S. electric utilities.     

房地产企业的债务风险分析——“恒大地产”个案为例

房地产通常为高负债行业。经济增长进入新常态后,“去库存”亦成为我国房地产行业2016年的主基调,且战略性重组势在必行。以恒大地产为代表的一批地产巨头已逐渐掌握行业话语权,并悄然开始战略转型。通过对恒大地产的财务数据,从偿债能力角度进行分析,可知恒大地产虽然各偿债能力指标变化不大,整体负债水平保持基本稳定,但由于永续债按香港交易所准则而计入权益,掩盖了其负债的真实水平,若将永续债调入负债,则资产负债率会剧增。2015年恒大集团的骄人业绩就得益于高负债的支撑,因此,房地产行业的财务风险防范尤为重要。     

Randomization tests in recursive response-adaptive randomization procedures

In a randomized clinical trial, response-adaptive randomization procedures use the information gathered, including the previous patients' responses, to allocate the next patient. In this setting, we consider randomization-based inference. We provide an algorithm to obtain exact p-values for statistical tests that compare two treatments with dichotomous responses. This algorithm can be applied to a family of response adaptive randomization procedures which share the following property: the distribution of the allocation rule depends only on the imbalance between treatments and on the imbalance between successes for treatments 1 and 2 in the previous step. This family includes some outstanding response adaptive randomization procedures. We study a randomization test to contrast the null hypothesis of equivalence of treatments and we show that this test has a similar performance to that of its parametric counterpart. Besides, we study the effect of a covariate in the inferential process. First, we obtain a parametric test, constructed assuming a logit model which relates responses to treatments and covariate levels, and we give conditions that guarantee its asymptotic normality. Finally, we show that the randomization test, which is free of model specification, performs as well as the parametric test that takes the covariate into account.     

能效标识对节能产品选择的引导效用分析——基于京东家电线上销售的实证检验

搜集冰箱、洗衣机、空调三种大家电的线上销售数据,通过描述性分析、组间差异比较、多元回归分析等方式分析能效标识的市场引导效果。结果显示消费者对不同等级家电产品的选择量存在差异,但不同能效等级间消费者满意度并无明显差异,能效等级并非是影响消费者选择和满意度的显著因素。     

家族涉入、继任CEO来源与企业财务报告质量

以社会情感财富理论与合法性视角为出发点,选择2008—2018年中国沪深两市A股上市家族企业为研究样本,考察家族涉入及继任CEO来源对企业财务报告质量的影响。研究发现：家族的所有权涉入及管理权涉入均对企业财务报告质量具有显著的负向影响。相比一代创始人CEO,家族二代继任CEO与职业经理人继任CEO均会提升家族企业的财务报告质量。此研究丰富了家族企业研究方面的文献,拓展了家族企业财务报告质量前沿问题的研究视野,同时为我国后一代时期的家族企业如何提升财务报告质量提供了参考。     

电动空调涡旋压缩机型线优化

选取我国三大经济区2001—2017年的数据,运用面板数据模型分析了政府财政、金融市场及其相互作用对区域自主创新能力提升的影响,结果表明:政府财政对自主创新能力的提升作用较金融市场更为显著,但三大经济区存在差异;就全国总体而言,金融支持效率指标在是否存在政府中介的情况下均不显著,金融市场对自主创新的支持效率还很低下;误差修正模型表明区域自主创新能力提升还受自身前期自主创新能力水平影响;人力资本的投入对区域自主创新能力的提升起到至关重要的作用。