劳动力禀赋、耕地破碎化与农户生态耕种决策行为

目的 为清晰识别影响农户生态耕种决策行为的影响因素，为我国农业可持续发展，加快耕地数量、质量和生态“三位一体”保护目标的实现提供参考。方法 文章利用江西省11市47县（区）共1 488份农户的调研数据，从农户劳动力禀赋结构转变和小农生产造成耕地破碎的两大社会现象切入，采用双栏模型将农户生态耕种决策行为分为采纳意愿和采纳程度两个阶段进行实证分析研究。结果 （1）以中位数为划分依据，有生态耕种采纳意愿的农户数占样本总数的67.20%，有采纳意愿的农户对10项具体生态耕种行为的平均采纳数为5.323项；（2）家庭总人口对农户生态耕种采纳意愿与采纳程度均呈负相关、劳动力人数均呈正相关，兼业程度对农户生态耕种采纳程度呈正相关，耕地破碎化对农户生态耕种采纳意愿呈负相关；（3）农户生态耕种决策行为还受到受教育程度、农业收入占比、是否加入合作社、是否享受农业补贴等因素影响。结论 政府及相关管理部门一方面应注重农户临时务工平台搭建，拓展相关信息视野以提升生态耕种采纳度；另一方面应规范和推动土地流转与土地整治，促进土地规模化经营，降低破碎度。     

Use of high-frequency data to evaluate the performance of dynamic hedging strategies

The hedging performance results of generalized autoregressive conditional heteroskedasticity models are mixed; we address this herein by adopting an asymptotic setting to determine the relative performance of competing hedge ratios. The proxy variable is constructed through precise realized measures rather than through noisy squared returns because the substitution of the latent true hedged portfolio variance with a noisy proxy renders the loss function incapable of ranking forecasts consistently. The merits of allowing some features in modeling the spot–futures distribution are assessed. Empirical comparisons suggest that hedgers may favor the wrong model when the quality of the proxy variable deteriorates.     

新财税政策下的职工基本养老保险最优缴费率测算研究

企业职工基本养老保险缴费率作为养老保险制度的关键性要素,受到专家学者的普遍关注,企业缴费率高、缴费压力大已成为制约企业发展的重要因素。本文综合运用灰色关联、因子分析与回归、动态调整和模拟预测的方法,构建企业基本养老保险缴费率适度水平的因子测算模型,以上海市2008—2019年的数据作为样本进行测算与预测。结果显示:缴费率的适度水平处于19%～23%;增加国有资产划转10%补充社保基金以及中央调剂金制度等参数后,模拟预测2018—2025年的缴费率适度水平在14.8%～18.6%之间,说明企业职工基本养老保险的缴费率有进一步下降的空间。     

Disentangling the impact of temperature on consumers' attitudes toward nostalgic advertising

Although the effect of temperature on consumers is ubiquitous, little is known about how temperature affects consumers' attitudes toward nostalgic advertising. Drawing on embodied cognition theory, this study explores the effect of temperature on consumers' attitudes toward nostalgic advertising through the mediator of the affective system. Based on two experiments involving personal and historical nostalgic advertising, our results show that when exposed to comfortable temperature, consumers follow the “assimilative effect” of temperature; warm temperatures trigger more positive attitudes toward nostalgic advertising when compared with cool temperatures. However, when exposed to uncomfortable temperatures, consumers follow the “complementary effect” of temperatures; cold temperatures lead to more positive attitudes toward nostalgic advertising than hot temperatures. Furthermore, the affective system plays a mediating role between temperature and consumers' attitudes toward nostalgic advertising. This study contributes to the literature on temperature in marketing and provides a practical guide for companies to implement nostalgic advertising strategies.     

Effects of shared characteristics between eco-labels: A case for organic and local food

Food labels are created to reduce information asymmetry and help consumers make better food choices. However, the labels may have unanticipated effects, especially when they share common characteristics that may introduce confusion in making food choices. This study investigates how perceived relationships between different food labels may affect the price premiums of organic and local attributes for milk and fresh strawberries. Results show that the impacts of perception vary by product and label, and different food labels could positively affect price premiums on organic and local products. Results provide policy implications for better labeling and educational programs to reduce inadvertent confusion and improve consumer decision-making.     

基于倾角影响线的简支梁桥损伤识别

为了推广影响线理论在结构损伤识别方面的应用,提出了一种基于简支梁桥损伤前后倾角影响线差值及差值曲率的损伤识别方法。对简支梁桥倾角影响线的概念进行定义,推导了简支梁桥损伤前后的倾角影响线公式,并对损伤识别指标进行公式推导,从理论上证明了将其用于损伤识别的可能性。为验证本文建立损伤识别指标的正确性,建立简支梁桥结构有限元模型进行分析。结果表明:简支梁桥损伤前后的倾角影响线差值在损伤区域出现峰值;简支梁桥损伤前后的倾角影响线差值曲率在无损伤区域均为0,在损伤区域均不为0。分析得出结论如下:简支梁桥损伤前后的倾角影响线差值用于判别损伤位置准确度较高;利用简支梁桥损伤前后的倾角影响线差值曲率不仅对单处损伤和多处损伤均具有良好的识别效果,而且可以实现对简支梁桥损伤程度的识别。     

Growth and optimal policies in an R&D-growth model with imperfect international capital mobility

In this paper, we examine the effects of international capital mobility on innovation, growth, and optimal growth policies in a small open economy with R&D-driven growth. Households can borrow funds from an imperfect international capital market to finance their investment in R&D firms. We show that the economy can reach a higher growth rate if international capital is more mobile. This result is consistent with recent empirical findings. Moreover, we show that the common growth-enhancing policies, such as patent protection and the R&D subsidies, have an additional negative welfare effect when households can access the international capital market. Accordingly, the optimal patent protection and R&D subsidy should be smaller when the degree of international capital mobility is higher.     

我国东中西部地区创新效率差异研究 ——基于电子及通信设备制造业产业聚集视角

利用2009-2019年我国电子及通信设备制造业省级面板数据，将产业创新过程划分为知识生产与成果转化两个阶段，利用区位熵指数对产业集聚度进行测量，通过Malmquist指数计算区域创新效率，构建两阶段知识生产模型，研究产业集聚对区域创新效率的影响。研究发现，产业集聚与区域创新效率并未呈现传统的东高西低分布特征，并且知识生产阶段的区域创新效率高于成果转化阶段。同时，面板随机前沿回归结果显示，产业集聚阻碍区域创新效率提升，不利于区域创新，而来自政府资金、政策等方面的支持会在知识生产阶段促进区域创新效率提升，在成果转化阶段阻碍区域创新效率提升。最后，根据研究结论，从政府与企业两个方面给出提高区域创新效率的相关建议。     

基于数据价值链的项目型企业数字化转型路径研究——以华为ISDP变革为例

数字经济深入推进使数字化转型成为企业发展的必然选择。针对传统项目型企业转型落后问题，构建项目型企业数字化转型路径，以华为公司项目数字化交付平台(ISDP)变革项目为例，基于数据价值链视角深入剖析企业在数字化转型时所面临的组织管理挑战和数据资源挑战，梳理华为基于ISDP变革的数字化转型内容。在此基础上，提出融合全域数据、规范数据标准、集成应用技术、释放数据价值四阶段路径，并建议项目型企业采用“构建业主—项目型企业—项目部数字纽带”“统一项目分解结构和编码体系”等方法进行变革转型，实现项目标准化，以期对项目型企业数字化转型理论和管理实践有所启示。