Stabilizing the market with short sale constraint? New evidence from price jump activities

We re-examine the impact of short-sale constraints (SSC) on market stabilization via realized jump activities during 2002–2009 to circumvent the reverse causality in identifying the policy effects of SSC. We observed that the abnormal downturns under tighter short sale constraints are significantly larger whereas there is no difference for abnormal upturns. Our empirical results survive across a sequence of robustness examinations controlled for market illiquidity. The findings do not support the claims by regulators that restraining short-sales can stabilize prices; instead, SSC has led to a less efficient market with stronger extreme downward returns.     

Making an exciting brand big: Brand personality,logo size and brand evaluation

This research examines how brand personality (excitement) and logo size used in product design (big versus small) interacts in affecting consumer brand evaluation. We first demonstrate that combining a big logo and a high-excitement brand (versus a small logo combined with a high-excitement brand) leads to high processing fluency, further resulting in more favourable brand evaluation (Study 1). We then determine the consumption situation as a moderator of such an interaction effect: the influence of the big logo and high-excitement-brand combination on brand evaluation is significantly weakened in a private consumption situation (a T-shirt worn at home) compared to a public consumption situation (a T-shirt worn outside, Study 2a), and becomes insignificant for a private product category (slippers, Study 2b).     

基于改进粒子群算法的无人机航迹规划

针对当前基本粒子群算法无人机航迹规划在后期收敛速度比较慢、效率不高、易陷入局部最优等问题,提出一种改进粒子群算法。首先,在迭代前期和后期分段设置惯性权值的调整,实现粒子惯性和寻优行为的平衡;其次,设置一个定值与相邻2次适应度函数最优值比较策略,防止陷入局部最优;最后,引入遗传算法的交叉、变异机制,得出更优的结果。并通过仿真验证了改进粒子群算法在三维空间航迹规划的有效性和可行性。结果表明,与其他航迹规划算法相比,新算法具有路径长度更短、耗时更少、路径更平滑等优点,加快了收敛速度,提高了航迹规划效率和稳定性。因此,改进算法的航迹规划可得到满足约束关系的最优航迹,对实现自主飞行有重要的参考价值。     

City Size,Population Concentration and Productivity: Evidence from China

This paper investigates the impact of China's city size and urban population concentration on city productivity by developing a distinctive index based on global nighttime light data. Using the panel data of 280 prefecture cities from 2004 to 2013 and employing dynamic system generalized method of moments and panel threshold model regression techniques, our results show that city size has a positive impact on city productivity; therefore, cities in China still have the potential to expand. While moderate urban population concentration can benefit city productivity, excessively concentrated urban population distribution may impede the growth of city productivity. We also find that the level of labor income significantly affects the impacts of urban agglomeration on labor productivity. Therefore, our results imply that city development policies should focus more on how to appropriately allocate economic activities and adjust population distribution in urban areas according to different stages of economic development.     

New perspectives on farm size and productivity

The farm size and productivity debate has been limited by the focus on land or labor productivity, generally showing respective productivity advantages to smaller or larger sized farms. Our purpose is to provide new perspectives on the debate by bringing together evidence from a set of novel case studies in both rich and poor countries. Common to them are the adoption of total factor productivity (TFP) as the comparative performance measure, and the reliance on panels of farm micro data. The present article presents a synthesis of findings from five case studies in (i) Malawi, Tanzania, and Uganda; (ii) Bangladesh; (iii) Brazil; (iv) Australia; and (v) the United States. The preponderance of evidence from these studies suggests that there is no single economically optimal agrarian structure; rather, it appears to evolve with the stage of economic development. Certain farm sizes face relative productivity advantages, such as small farms in Africa. But with economic and market growth, that smallholder advantage will likely attenuate, moving toward constant and eventually increasing returns to size. Yet, importantly, small farms may be quite dynamic, and need not be a drag on agricultural growth until perhaps well into the development process.     

Pareto efficient allocation of an in-motion wireless charging infrastructure for electric vehicles in a multipath network

Electric vehicles (EV) use an eco-friendly technology that limits the greenhouse gas emissions of the transport sector, but the limited battery capacity and the density of the battery are the major barriers to the widespread adoption of EV. To mitigate this, a good method seems to be the innovative wireless charging technology called ‘On-Line EV (OLEV)’, which is a contactless electric power transfer technology. This EV technology has the potential to charge the vehicle’s battery dynamically while the vehicle is in motion. This system helps to reduce not only the size of the battery but also its cost, and it also contributes to extending the driving range before the EV has to stop. The high cost of this technology requires an optimal location of the infrastructure along the route. For this reason, the objective of this paper is to study the problem of the location of the wireless charging infrastructure in a transport network composed of multiple routes between the origin and the destination. To find a strategic solution to this problem, we first and foremost propose a nonlinear integer programming solution to reach a compromise between the cost of the battery, which is related to its capacity, and the cost of installing the power transmitters, while maintaining the quality of the vehicle’s routing. Second, we adapt the multi-objective particle swarm optimization (MPSO) approach to our problem, as the particles were robust in solving nonlinear optimization problems. Since we have a multi-objective problem with two binary variables, we combine the binary and discrete versions of the particle swarm optimization approach with the multi-objective one. The port of Le Havre is presented as a case study to illustrate the proposed methodology. The results are analyzed and discussed in order to point out the efficiency of our resolution method.     

基于能量消耗分析的乳状液液滴粒径计算关系式

在油水混输管道中,存在着大量粒径大小不一的乳状液液滴,液滴粒径及分布对油水混合液的粘度有重要影响,从而在很大程度上影响管道的压降。因此,研究乳状液液滴粒径的计算关系式对于描述油水两相的流动特性以及准确计算管道压降具有重要意义。针对4种原油,通过油水体系的乳化实验,研究了搅拌转速、温度及含水率对乳状液液滴粒径的影响。研究发现,搅拌转速增大,乳状液液滴粒径减小;温度升高,乳状液液滴粒径增大,并且在低温下增大的趋势较显著;含水率增加,乳状液液滴粒径有减小趋势,但减小的幅度不大;以火用损率来表征剪切过程中的能量消耗,建立了基于剪切火用损率分析的乳状液液滴粒径计算关系式。     

Listen to their heart: Why does active listening enhance customer satisfaction after a service failure?

A service employee’s active listening plays a crucial role in restoring a damaged customer relationship. However, previous studies reveal little about how listening to customer complaints operates in recovering a service failure. The purpose of this research is to explore when and why the employee’s active listening has a positive influence on customer response. We define active listening as (1) listening to customers’ concerns before apologizing and (2) verbally acknowledging them. Using scenario-based experiments, we demonstrate that active listening improves customer satisfaction, which in turn increases tip size (Study 1). Moreover, we find that active listening fosters customers’ perceptions of preferential treatment, which lead to greater customer satisfaction (Study 2). Yet, such positive effects of active listening diminish when customers are unexpectedly offered a complimentary service such as a room upgrade. The implications for academic researchers and marketing managers are discussed.     

Rising real wages,mechanization and growing advantage of large farms: Evidence from Indonesia

This paper examines dynamic patterns of land use, capital investments and wages in agriculture using farm panel data from Indonesia. The empirical analysis shows that with an increase in real wages that prevailed in both agricultural and non-agricultural sectors in rural areas, relatively larger farmers increased the size of operational farm land by renting in land as well as used more hired-in machines through machine rental and/or service providers, which induces the substitution of labor by machines. Machines and land are complementary and, consistently, the inverse farm size-productivity relationship tends to be reversed among relatively large holders. The results support growing (diminishing) advantage of large (small) farms in the presence of rapidly rising real wages and have food security policy implications to many Asian countries where real wages are rapidly rising and small farms are predominant.