突发事件情境下中国消费者冲动性购买行为研究

目的/意义消除公众非理性行为对于战胜突发公共卫生事件影响具有重要作用。设计/方法以COVID-19疫情为情境,采用扎根理论解析社交平台上的新闻和在线评论,以SOR模型为基础构建突发公共卫生事件中公众非理性行为生成机制的理论模型,并开展系统化阐释。结论/发现公众非理性行为生成机理遵循“突发事件情境刺激—非理性行为决策—非理性行为实施—非理性行为调控”的逻辑过程。信息源、信息传播渠道影响公众对事件信息的处理质量,事件响应发挥了调节作用;公众非理性行为决策是一个复杂过程,公众信息处理质量直接影响其心理认知评判,但受到心理距离的正向调节;情绪反应是公众非理性行为的前提,风险认知、责任认知和损益认知带来公众非理性情绪反应,但反应程度因个体性格、知识和先前经验的不同而不同;非理性行为可能由非理性情绪直接诱发,也可能经过行为评估后实施,前者主要体现为情绪聚焦型行为,后者则反映为问题聚焦型和利益聚焦型行为。加强非理性行为调控,有助于调整公众非理性情绪,减少非理性行为发生,加速人类全面战胜疫情。     

突发危机事件网络舆情治理的多情景演化博弈分析

互联网时代，网络媒体已经成为谣言传播的重要载体，严重威胁到我国的网络空间安全和社会和谐稳定，因此加强和创新对网络媒体的监管，妥善治理突发危机事件网络舆情是各级政府面临的重大挑战。针对突发危机事件网络舆情治理的研究，本文运用演化博弈理论构建了网络媒体与地方政府双方演化博弈模型，在引入中央政府惩罚机制基础上，对比分析了网络媒体与地方政府双方行为策略选择的演化稳定均衡，同时采取多案例进行实证研究，并通过数值仿真分析对模型进行多情景推演模拟。研究结果表明：突发危机事件网络舆情传播热度与网络媒体和地方政府双方的策略选择有着直接关系；若地方政府承受突发危机事件网络舆情恶性演化造成的经济损失与信誉损失持续增大，双方演化系统都会出现周期性波动现象；引入中央政府惩罚机制后，其惩罚力度若高于网络媒体消极应对网络舆情所受到的惩罚和地方政府的监管投入成本时，最终系统会演化至良性状态，研究结论为政府部门在面对突发危机事件网络舆情治理方面提供了新思路。     

An empirical saddlepoint approximation based method for smoothing survival functions under right censoring

The Kaplan–Meier (KM) estimator is ubiquitously used for estimating survival functions, but it provides only a discrete approximation at the observation times and does not deliver a proper distribution if the largest observation is censored. Using KM as a starting point, we devise an empirical saddlepoint approximation‐based method for producing a smooth survival function that is unencumbered by choice of tuning parameters. The procedure inverts the moment generating function (MGF) defined through a Riemann–Stieltjes integral with respect to an underlying mixed probability measure consisting of the discrete KM mass function weights and an absolutely continuous exponential right‐tail completion. Uniform consistency, and weak and strong convergence results are established for the resulting MGF and its derivatives, thus validating their usage as inputs into the saddlepoint routines. Relevant asymptotic results are also derived for the density and distribution function estimates. The performance of the resulting survival approximations is examined in simulation studies, which demonstrate a favourable comparison with the log spline method (Kooperberg & Stone, 1992) in small sample settings. For smoothing survival functions we argue that the methodology has no immediate competitors in its class, and we illustrate its application on several real data sets. The Canadian Journal of Statistics 47: 238–261; 2019 © 2019 Statistical Society of Canada     

Smooth tests for the gamma distribution

The gamma distribution is often used to model data with right skewness. Smooth tests of goodness of fit are proposed for this distribution. Their powers are compared with powers of the Anderson–Darling test and tests based on the empirical Laplace transform, the empirical moment generating function and the independence of the mean and coefficient of variation that characterizes the gamma distribution.     

Economic Impact of Rural to Urban Labor Migration in China from 1991 to 2011

This paper quantitatively explores the size of rural labor force transfer and the specified flow nonagricultural industries, and the corresponding contribution of the increase of labor force utilization and productivity to economic growth from 1991 to 2011. The transfer size increased from 86.73 million people in 1990 to more than 250 million people in 2011. In 2011, 53.7% of the transfer labor worked in second industry, the others in third industry. By using growth accounting, this paper decomposes GDP growth into three growth components: working age population, labor force productivity and labor force utilization. Firstly, the paper calculated the real average annual growth rate of these three factor from 1991 to 2011 and their contributions to GDP growth. Then we calculated the changes of three factors and GDP'growth rates under the scenario without rural labor transfer, and finally got the contribution of rural labor transfer to GDP growth by comparing the difference between real and assumption scenario. The resuit shows that from 1991 to 2011, the real average annual growth rate of three factors were 1.3%, 9.3% and-0.3%, and their contribution the GDP growth was 12.2%, 90.2% and-2.4%separately. Under the scenario without rural labor transfer, the average annual growth rates of labor force productivity and labor force utilization would reduce to 8.9% and-1.4%, while the GDP average annual growth rate would reduce from 10.3% to 8.8%. The profound analysis in details shows that the transfer promoted labor force utilization by 30.7%and productivity by 23.9% annually on average, therefore promoting GDP by 63.7%, and GDP growth rate by 1.6% annually on average. On the one hand, through the utilizing of the ‘surplus rural labor force', the transfer promoted the labor force utilization, then made the potential population dividend brought by the increase of working age population size practical; on the other hand, through promoting of labor force industry structure, the transfer promoted the total productivity. The transfer has been and will be an important driving force of economic growth in China.     

Exact distribution of the convolution of negative binomial random variables

In this note, we derive the exact distribution of S by using the method of generating function and BELL polynomials, where S = X₁ + X₂ + ??? + X_n, and each X_i follows the negative binomial distribution with arbitrary parameters. As a particular case, we also obtain the exact distribution of the convolution of geometric random variables.     

The generalized transmuted-G family of distributions

We introduce a new class of continuous distributions called the generalized transmuted-G family which extends the transmuted-G class. We provide six special models of the new family. Some of its mathematical properties including explicit expressions for the ordinary and incomplete moments, generating function, Rényi and Shannon entropies, order statistics and probability weighted moments are derived. The estimation of the model parameters is performed by maximum likelihood. The flexibility of the proposed family is illustrated by means of three applications to real data sets.     

The exponentiated transmuted-G family of distributions: Theory and applications

In this paper, a new family of continuous distributions called the exponentiated transmuted-G family is proposed which extends the transmuted-G family defined by Shaw and Buckley (2007). Some of its mathematical properties including explicit expressions for the ordinary and incomplete moments, generating function, Rényi and Shannon entropies, and order statistics are derived. Some special models of the new family are provided. The maximum likelihood is used for estimating the model parameters. We provide the simulation results to assess the performance of the proposed model. The usefulness and flexibility of the new family is illustrated using real data.     

Saddlepoint approximations to tail expectations under non-Gaussian base distributions: option pricing applications

The saddlepoint approximation formulas provide versatile tools for analytic approximation of the tail expectation of a random variable by approximating the complex Laplace integral of the tail expectation expressed in terms of the cumulant generating function of the random variable. We generalize the saddlepoint approximation formulas for calculating tail expectations from the usual Gaussian base distribution to an arbitrary base distribution. Specific discussion is presented on the criteria of choosing the base distribution that fits better the underlying distribution. Numerical performance and comparison of accuracy are made among different saddlepoint approximation formulas. Improved accuracy of the saddlepoint approximations to tail expectations is revealed when proper base distributions are chosen. We also demonstrate enhanced accuracy of the generalized saddlepoint approximation formulas under non-Gaussian base distributions in pricing European options on continuous integrated variance under the Heston stochastic volatility model.     

自媒体互动广告的场景化思维与应用

自媒体的勃兴加剧了网络生态的碎片化,技术的进步则打开信息传播的场景化视域。传统场景的数字化重构和新场景的细分、裂变给互动广告营销带来新的挑战与机遇。自媒体互动广告的场景化既有来自用户的主观需求因素,也有体验经济模式的客观驱动因素,由“场景五力”等技术所支撑的自媒体平台为各种类型化场景建设提供了基础。场景化广告拥有特定性、体验性、共享性、跨界性等互动特征。自媒体互动广告的场景化应用实践是一个动态的系统过程,包括用户导向的场景构建、需求导向的信息匹配传播、体验导向的品牌推广等多个环节。通过特定的场景化运营能发挥互动传播优势,提升广告效果。