The socio-economic determinants of COVID-19: A spatial analysis of German county level data

The study explores the association of socioeconomic, demographic, and health-related variables at the regional level with COVID-19 related cases and deaths in Germany during the so-called first wave through mid-June 2020. Multivariate spatial models include the 401 counties in Germany to account for regional interrelations and possible spillover effects. The case and death numbers are, for example, significantly positively associated with early cases from the beginning of the epidemic, the average age, the population density and the share of people employed in elderly care. By contrast, they are significantly negatively associated with the share of schoolchildren and children in day care as well as physician density. In addition, significant spillover effects on the case numbers of neighbouring regions were identified for certain variables, with a different sign than the overall effects, giving rise to further future analyses of the regional mechanisms of action of COVID-19 infection. The results complement the knowledge about COVID-19 infection beyond the clinical risk factors discussed so far by a socio-economic perspective at the ecological level.     

Unfolding Patterns of Unpaid Household Work in Latin America

Although Colombia, Mexico, Peru, and Uruguay show similar empirical patterns in terms of time women devote to unpaid work, they also present important variations in how unpaid work is distributed between men and women. Using time-use surveys for the 2007–10 period, this study finds a uniform pattern across the four countries regarding the main individual-level variables related to the allocation of unpaid work. When decomposing the gender gap in hours devoted to unpaid work, most of the difference cannot be attributed to variations in observable characteristics of men and women: the unexplained part of the gap is the dominant part. Results suggest that both the strength of traditional gender roles and existing welfare architecture are relevant factors in understanding variations in how unpaid work is distributed between men and women in these four countries. The results reaffirm that powerful interventions are needed to shift gender norms about unpaid work.     

Market microstructure in a global B2B network

On‐line marketplaces raise several interesting issues, among them the relevance of location when content is digitized, and the assessment of a supplier's capabilities when buyers worldwide only have electronic contact with sellers. In global B2B on‐line marketplaces, market microstructures, i.e. which firms compete for the same customers, are thus likely to be influenced by how customers value location and firm capabilities in their decisions to do business with different suppliers on‐line. We suggest that both these sets of attributes will continue to matter on‐line—firms possessing similar capabilities, as well as firms that are similar in location by country, time zones or clusters, will compete for business from the same customers. We model the similarity in competitive positions between pairs of firms based on the overlap in their customer networks, using data on actual interactions between supplier and customer banks on an electronic trading system. Using QAP network regression techniques on the 100 largest banks in this industry, we find that similarity in capabilities influences who competes with whom, and that location still matters in a global B2B exchange. Interestingly, location influences who a firm's competitors are, but not where its customers are from. Copyright © 2001 John Wiley & Sons, Ltd.     

Income and substitution effects of fiscal policy on work effort

The focus of this paper is twofold. First, it examines the impact on work effort of changes in government purchases financed with lump‐sum taxes, in a neoclassical framework, with respect to four industrialised countries. Second, it reconsiders the expenditure–work effort relationship in a broader conceptual context that allows for distortionary taxation and a disaggregation of the income and substitution effects. Our findings are shown to cast doubt on the empirical plausibility of the prevailing (neoclassical and New Keynesian) models which seem to rely heavily on the lump‐sum tax notion, thus ignoring the substitution effects of distortionary taxation.     

服务业集聚与产业结构优化关系探究

随着全球化进程的不断加快，服务业集聚已经成为人们普遍关注的话题。产业集聚在获得规模效应的同时避免了垄断现象的产生，服务业集聚不但拥有这样的优势，而且还有自己独特的形成和发展特点。从产业结构的优化角度切入，借助区位商和专门化率等分析指标，以江苏省和上海市为例，对服务业集聚的形成进行理论和实证分析，提出产业结构的优化对于服务业集聚的形成和发展有着积极的作用。合理的产业结构能够为服务业集聚提供坚实的基础，各地区应该根据各自的产业特点积极的进行优化，催生服务业集聚，加快本地区经济的进一步发展。     

Spatial determinants of Japanese FDI in China

Research on foreign direct investment in China has spawned an increasingly large literature. Whilst regional cleavages with respect to the distribution of foreign direct investment (FDI) are acknowledged, empirical research on the spatial determinants of FDI in China has been limited. Furthermore, research on the spatial determinants of home country FDI in China has thus far been neglected due to difficulties in accessing the appropriate data. The objective of this paper is to examine the spatial determinants of Japanese direct investment in China by using an econometric model. To that purpose, a dataset is created from the Toyo Keizai directory on the overseas activities of Japanese companies. The results show that tertiary education, inland waterways, as well as coastal location are positive and significant determinants of Japanese investment in China.     

企业空间集聚的成因分析

企业空间集聚是当今世界区域经济发展的重要特色。本文从同行业和不同行业两个角度分别探讨了企业空间集聚的成困,并实例分析了徐州市金山桥开发区企业集聚体的形成与发展。     

Asymptotic expansion of S-estimators of location and covariance

By means of a straightforward application of empirical process theory, we show that S-estimators of multivariate location and covariance are asymptotically equivalent to a sum of independent vector and matrix valued random elements respectively. This provides an alternative proof of asymptotic normality of S-estimators and clearly explains the limiting covariance structure. It also leads to a relatively simple proof of asymptotic normality of the length of the shortest α-fraction.     

物流配送系统中的运筹学问题及方法研究

物流配送系统中包含诸多运筹学问题,如配送中心选址中的0-1规划问题,货物配载中的背包问题,配送路线优化中的动态规划问题等,通过建立数学模型,利用运筹学方法与信息技术的结合可对上述问题加以解决,为配送业务的进一步发展提供帮助.     

模型算法在企业的场址选择及其内部设施的平面布置中的应用

企业的场址选择及其内部设施的平面布置形式，对于企业的运输费用具有举足轻重的作用。本文对企业和内部设施的布置进行模型设计，并通过层次分析法对场址选择方案进行比选．采用对目标函数的优化对企业内部设施的平面布置形式进行优化。