Together alone: a group-based polarization measurement

Quality & Quantity - The growing polarization of our societies and economies has been extensively studied in various disciplines and is subject to public controversy. Yet, measuring...     

零工经济时代数字平台控制劳动力的供给行为

本文首先基于委托-代理模型构建了一个数字平台控制劳动力供给的行为经济学模型,从理论上分析了数字平台控制劳动的方式和心理机制;然后建立了一个赫克曼(Heckman)选择模型,利用Uber的大数据实证分析了网约车司机的劳动决策.研究结果表明:(1)在零工具有参考点偏好的前提下,数字平台通过高货币激励或高目标奖励使零工劳动者的参考点具有适应性,进而避免其过早地陷入“收入目标”行为;(2)数字平台利用零工劳动者的厌恶损失偏好,对其实施控制以延长工作时间;(3)网约车司机存在“收入目标”行为,且该行为呈现出动态性的特点;(4)收入激励和“峰时”溢价对网约车司机的工作概率和工作时间具有显著的正影响,且在一天的某个时间段内能够抑制网约车司机的“收入目标”行为.可见,零工经济时代到来,一方面提高了劳动力资源配置效率;另一方面,数字平台通过劳动控制变相延长了零工的劳动时间,加剧了剥削.     

Box-Behnken响应面法优化徐长卿配方颗粒挥发油-β-CD包合物制备工艺

为了解决徐长卿挥发油加油难及加入后的稳定性问题,采用Box-Behnken响应面法,优选出徐长卿配方颗粒挥发油-β-CD包合物的制备工艺。在单因素试验的基础上,采用3因素3水平Box-Behnken设计对徐长卿配方颗粒挥发油-β-CD包合工艺进行优选,以挥发油包合率及包合物收率为考察指标,考察挥发油与β-CD比例、包合温度、包合时间对结果的影响。结果表明:优选的包合工艺条件为挥发油与β-CD质量比为1∶8.34,包合温度为50.2℃,包合时间为2.17 h。在此条件下,挥发油包合率为72.19%,包合物收率为75.06%,综合评分为96.41,RSD值为1.1%。优选的包合工艺包合率高,工艺稳定可行,可为配方颗粒挥发油的工业化生产提供数据支持。     

The major determinants of logistic performance in a global perspective: evidence from panel data analysis

The global logistics industry has grown significantly and logistics has become an important sector of the business economic system and a major global economic activity in recent years. Logistics activities accelerate economic and productivity growth. Efficient logistics is also important to a country’s competitiveness and source of employment. The purpose of this paper is to uncover and understand the major determinants of logistics performance (LP) to further lift the LP of countries. Using unbalanced panel data of 93 selected countries from 2007 to 2014, the present research attempts to critically investigate the major determinants of LP. In estimating the model, this study prefers to use static panel data approach owing to limited data. The findings of the present study reveal that (a) countries with low level of corruption and stable political environment are likely to yield a high level of LP; (b) improvement in resources supply such as infrastructure, technology, labour, and education also have a significant positive effect on LP. Therefore, institutional reforms and upgrading resources will effectively accelerate LP.     

基于循环经济的绍兴休闲观光农业发展研究

［目的］休闲观光农业建设是绍兴市产业转型升级的关键一步，探寻休闲观光农业新模式，能够为休闲农业发展提供理论参考。［方法］文章采用变异系数法确定指标权重，多因素综合分析法测算观光农业发展水平，从循环经济角度出发，评价2001—2016年绍兴市休闲观光农业发展可持续性，提出发展中存在的问题并探索循环型的休闲观光农业新模式。［结果］（1）2001—2016年以来，经济发展可持续性得分较高，资源环境可持续得分次之，循环经济可持续发展偏低。（2）现阶段绍兴市休闲观光农业发展主要存在休闲观光农业自然环境不断遭到破坏，休闲观光农业缺乏整体规划，休闲观光农业旅游支撑体系不够健全等问题。（3）未来发展中，循环经济发展下的休闲观光农业可以开发建设时空复合循环型、资源综合利用循环型、能量多级利用循环型、综合开发利用循环型等4种模式。［结论］未来绍兴市应将循环经济的理念融入到休闲观光农业中，因地制宜，科学选择循环型休闲观光农业发展模式； 规划先行，科学利用农业旅游资源； 强化保障，建立休闲观光农业支撑体系，全面推动休闲观光农业健康持续发展。     

Advance selling of new products to strategic consumers on flash sale platforms*

Flash sale (FS) is a new business model that offers discounted products in limited numbers over a short period. In this paper we discuss the impact of strategic consumers on advance selling (AS) of new products on FS platforms. We first study the impact of strategic consumers on competing retailers adopting AS to sell a homogeneous new product. And find that the retailers’ AS profits and inventory quantities decrease with the strategic customers’ valuation and valuation decreasing rate. Then we analyse whether FS can mitigate the impact of strategic customers on retailers adopting AS for new products. We consider a newsvendor model involving only one retailer adopting AS to sell a new product. We derive the results by comparing this model with two counterpart models, namely the classical newsvendor model with no strategic customers and a newsvendor model with strategic customers where the retailer does not use FS under AS.     

The impacts of governance and institutions on inbound tourism demand: evidence from a dynamic panel data study

This study explores the impact of governance and institutions on inbound tourism demand in Malaysia using a dynamic panel data approach for 45 tourism source countries over the period 2005–2015. The results show that institutions play a very important role in explaining the behaviour of inbound tourism demand. To obtain a better picture, we investigate the response of international tourists to disaggregated institutional quality. We find that international tourists are more concerned about political stability, governmental effectiveness, regulations, laws, and corruption than voice and accountability. Therefore, policymakers should focus on ways to improve institutional quality to significantly increase international tourist arrivals.     

Irreversible investment,ambiguity and equity default swaps

We study the impact of ambiguity on the pricing and timing of the option to invest. There is a funding gap to undertake the investment, which is covered by entering into an equity-for-guarantee swap. Our model predicts that the more ambiguity-averse the agents, the less the option value, the later the investment and the higher the guarantee cost and the leverage. If the entrepreneur is more ambiguity-averse than the insurer, the investment threshold slightly rises as the perceived ambiguity increases, and on the contrary, if the entrepreneur is less ambiguity-averse than the insurer, the investment threshold increases sharply as the perceived ambiguity rises.     

全过程、立体化校企合作培养高职旅游人才的探索与实践

本文对高职旅游专业人才培养亟待通过校企合作解决的问题进行分析,回顾北京经济管理职业学院旅游管理专业2004年开办以来进行的相关探索,在此基础上提炼出全过程、立体化校企合作培养高职旅游人才机制,并对机制运行的实践效果进行总结,以期对高职旅游人才培养提供可借鉴的有效经验.     

微波提取酵母胞内甘油的分析方法初探

本文探讨了面包酵母胞内甘油分析的预处理方法——微波破碎法。通过单因素实验分析,确定了胞内甘油的提取条件:酵母细胞用微波破碎3次、每次破碎10 s、间隔5 s,然后用10 mL蒸馏水提取30 min得到胞内甘油,此法简便、易提取,适用于天然产物的快速提取。