What is the policy improvement of China’s land consolidation? Evidence from completed land consolidation projects in Shaanxi Province

Land consolidation plays an important role in increasing cultivated land, improving cultivated land quality and the ecological environment, and promoting the coordinated development of urban and rural areas. However, under the conditions of three decades of land consolidation being conducted and changing urban–rural human–land relationship, the areas of improvement in the land consolidation policy of China must be studied. This article analyzes the implementation and distribution characteristics of the land consolidation project completed in Shaanxi Province in 2018. Results show that land consolidation projects in Shaanxi are mainly land reclamation projects, cropland consolidation projects, and high-standard cropland consolidation projects. The increased cultivated land is mainly from land reclamation projects and cropland consolidation projects. The land consolidation projects in Aeolian Plateau Area, Loess Plateau Area, and Da Ba Mountain Area are mainly land reclamation projects. The land reclamation projects in Guan Zhong Plain Area and Qing Ling Mountain Area account for a large proportion. The spatial distribution of rural settlement consolidation projects, and rural settlement consolidation and land reclamation projects are mainly located in Guan Zhong Plain Area and distributed in the boundary area of Guan Zhong Plain Area and Loess Plateau Area. According to the characteristics of land consolidation projects and the changes of urban–rural human–land relationship, China should be prudent in or stop advancing land reclamation to increase cultivated land; cropland consolidation and high-standard cropland construction are vital ways to achieve China’s food security; and rural settlement consolidation should be carefully conducted in remote areas under the background of urbanization.     

锚企业与科技新城共生模式研究:以阿里巴巴和杭州未来科技城为例

以阿里巴巴和杭州未来科技城为例，采用Logistic模型探讨锚企业与科技新城共生模式，结果表明：总体而言，阿里巴巴和未来科技城属于互利共生模式，阿里巴巴成长会促进未来科技城发展，而未来科技城发展也会反哺阿里巴巴的成长。2013-2016年两者共生系数之间的差值不断缩小，表明阿里巴巴和杭州未来科技城的共生模式从偏利共生转向互利共生。     

Paired comparison models with age effects modeled as piecewise quadratic splines

We propose new models for analyzing pairwise comparison data, such as that relating to sports. We focus on changes in players’ strengths and the prediction of future results. Our models are based on the Thurstone-Mosteller and Bradley–Terry models, and make use of the time variation in the parameters. Furthermore, we apply our models to data from the Japanese traditional sport sumo, and analyze this data. The proposed models perform better than the standard Thurstone-Mosteller and Bradley–Terry models according to both the Akaike information criterion and the Brier score. We compare the proposed models in detail by focusing on individual sumo wrestlers.     

Bayesian selection of technology assumptions for the transformation from supply-use to input–output tables

ABSTRACT

In the construction of input–output models from supply-use tables, technology assumptions disambiguate how an industry uses inputs in the production recipe of multiple outputs. This paper uses Bayes' theorem to select technology assumptions, taking into account empirical observations. The paper presents a formulation to explore hybrids between product and industry technology assumptions in product-by-product tables. We then present Markov chain Monte-Carlo techniques to implement the Bayesian method for selecting technology assumptions. We apply the method in a case study using Eurostat supply-use tables of 2004 and 2005, exhibiting a volume of secondary products of less than 13%, and 59 products and industries per country. The results show that the choice of technology is not important, given that there is no strong evidence in favour of any of them.     

数字经济对区域创新绩效及其空间溢出效应的影响

数字化时代的经济运行方式呈现出数据驱动、万物互联、创新迭代的特征，数字经济的数字化、网络化、智能化属性对创新活动产生了深刻影响。运用空间杜宾模型，对361座城市2010-2018年度数据进行实证检验。检验结果表明，数字经济发展不仅能够带动本地创新绩效提升，而且对周边城市创新绩效也具有显著正向影响；与中、西部地区相比，东部地区数字经济对创新绩效的促进作用更强，空间溢出效应也更显著。由此，建议可从挖掘数据要素价值、搭建数字化平台、推动数字技术创新等角度发展数字经济，促进本地区和周边地区创新绩效共同提升。     

NVC龙企功能升级模式演进及机理纵向案例研究——技术自主性视角

国内龙头企业核心技术自主可控成为制约NVC（国内价值链）功能升级的关键问题。通过文献归纳，以能力自主与产权自主解构技术自主性内涵，并根据产品平台与技术轨道双维度划分NVC龙企功能升级模式。基于“能力—战略—行为—绩效（RSCP）”分析框架，选取华为海思公司作为纵向案例研究对象，探索技术自主性视角下NVC龙企功能升级模式及演进机理。结果发现，模块创新与知识产权创造能力通过产品渐进升级模式提升供应链；架构创新与知识产权布局能力可以调整技术轨道，通过产品突破升级模式I打通创新链；架构创新、模块创新和知识产权运营能力可以变革技术轨道，通过产品突破升级模式II主导价值链。     

科技企业孵化器何以激活区域创新——风险投资与孵化基金的中介作用

完善创新生态系统、提升区域创新能力是我国科技企业孵化器建设的重要目标。基于2013-2018年中国（内地）30个省份面板数据，采用面板数据模型实证检验科技企业孵化器是否促进了区域创新能力提升，并基于中介效应模型探讨风险投资和孵化基金在其中的间接作用。结果发现：①科技企业孵化器建设显著提升了区域创新水平，但主要增加的是实用新型和外观设计专利申请授权数总量，对发明专利申请授权数并没有显著促进作用。上述结果在剔除直辖市样本、采用随机效应模型及空间计量模型的稳健性检验后依然成立；②通过中介效应模型检验发现，区域风险投资和孵化基金集聚效应是科技企业孵化器影响区域创新水平的主要机制；③科技企业孵化器对区域创新的影响在不同区域间差异较大，在东部地区的创新激励效应更加显著，而且政策工具强度对科技企业孵化器与区域创新水平的关系具有正向调节作用。     

Correction to: Optimal and robust combination of forecasts via constrained optimization and shrinkage

We provide a correction to Proposition 1 in Optimal and robust combination of forecasts via constrained optimization and shrinkage, published in the International Journal of Forecasting 38(1):97-116 (2021). This correction has no impact on any other result (neither theoretical nor empirical) provided in the above paper.     

Combining forecasts for universally optimal performance

There are two potential directions of forecast combination: combining for adaptation and combining for improvement. The former direction targets the performance of the best forecaster, while the latter attempts to combine forecasts to improve on the best forecaster. It is often useful to infer which goal is more appropriate so that a suitable combination method may be used. This paper proposes an AI-AFTER approach that can not only determine the appropriate goal of forecast combination but also intelligently combine the forecasts to automatically achieve the proper goal. As a result of this approach, the combined forecasts from AI-AFTER perform well universally in both adaptation and improvement scenarios. The proposed forecasting approach is implemented in our R package AIafter, which is available at https://github.com/weiqian1/AIafter.     

Spatial price mimicking on Airbnb: Multi-host vs single-host

This paper studies the existence of two different supply operators in the peer-to-peer accommodation rental market for the city of Madrid. We specifically analyse spatial dependencies in price formation and whether the so-called professional hosts (i.e. those who have several Airbnb listings) set prices differently from single-property hosts. To this end, hedonic price models are estimated with and without spatial price dependence. Listings’ structural characteristics and accessibility measures to transportation hubs and sightseeing spots are considered in the regressions. Results provide clear evidence that price mimicking is higher among non-professional hosts whereas professional hosts set prices more independently.