纵向分离能否提高企业全要素生产率?——基于电力产业"厂网分开"的研究

中国电力行业一直延续纵向分离的改革路径，继发电环节从一体化垄断结构中分离之后，2015年新一轮的电力体制改革又提出输配售电业务分离、推进电力市场化交易的目标。不同纵向结构下，电力产业链上下游企业的博弈均衡显示纵向分离改革可提高上游发电环节的竞争性，减少效率损失。进一步基于微观发电企业数据，通过双重差分及倾向得分匹配模型考察“厂网分开”这一准自然实验的效果，研究结果显示，纵向分离改革显著提升了发电企业的效率。现阶段应继续推进输配售分离改革，通过供给侧和需求侧的互动响应使上游发电环节的效率收益纵向传递，提高消费者福利。     

Heterogeneity and netting efficiency under central clearing: A stochastic network analysis

This paper examines the effect of heterogeneity in clearing members’ exposure management practices under central clearing. Our network model specifies the dynamics of prenetted interbank exposures to shape interdependent exposure distributions beyond normality. Employing over-the-counter derivatives market data from the U.S. Office of the Comptroller of the Currency, our simulation results indicate that heterogeneity in bank-to-bank exposure dynamics is systemically desirable, while the entire system benefits more from the central clearing in more homogeneous environments. Policymakers should incentivize individual clearing members to enhance resiliency and stability in counterparty exposure management to maximize netting efficiency under central clearing.     

Fiscal rules and budget forecast errors of Italian municipalities

We study the impact of the domestic stability pact on the accuracy of budget forecasts of Italian municipalities. Identification of the causal effect exploits a quasi-natural experiment generated by the removal in 2001 of the fiscal restraints on budget decisions for municipalities with fewer than 5000 inhabitants and by stricter budgetary restrictions and severe penalties for noncompliers in 2002. We find that relaxing fiscal rules had a sizeable impact on budget forecast errors, especially in 2002. In fact, revenue (expenditure) forecast errors for municipalities with fewer than 5000 inhabitants became 26% (22%) larger than in the past.     

铬掺杂对硅酸铁锂电学性能影响的计算机仿真研究

硅酸铁锂是一种锂离子电子的正极材料,由于其晶胞在理论上可允许可逆脱嵌两个锂原子,使得其理论比容量有巨大的提升空间,加上原料易得、无污染及成本低的优势,受到了人们的重视。正极材料掺杂被认为是改善其导电性能的有效途径。论文通过运用基于第一性原理方法的计算机仿真技术,对铬掺杂硅酸铁锂的结构和导电性能的影响进行了计算机仿真研究,结果表明未掺杂的硅酸铁锂其带隙快读为2.44eV,掺杂铬之后硅酸铁锂带隙减小为2.31eV,表明铬掺杂可提高硅酸铁锂的导电性能。     

基于声誉效应的工程监理激励机制模型研究

为了提高工程监理工作积极性,基于Holmstrom-Milgrom模型,引入声誉效应,建立声誉效应和显性激励机制相结合的动态委托代理激励模型。分析声誉效应发挥激励机制作用条件,并与未考虑声誉效应的委托代理模型进行比较。结果表明:声誉效应在满足一定的条件下,引入声誉激励机制能够增加业主的期望收益,并且能提高监理的努力水平。最后,通过数值仿真模拟验证引入声誉效应的合理性。     

刺芪参胶囊的制备工艺研究

目的:探索刺芪参胶囊的制备工艺。方法:采用正交实验,以总皂苷质量为指标,优化提取工艺;采用单因素实验优化制剂工艺。结果:在最佳提取工艺条件下,刺芪参胶囊提取物中的总皂苷含量为12.19 mg·g-1;以糊精作为填充剂、硬脂酸镁为助流剂、95%乙醇为黏合剂制备胶囊剂。结论:刺芪参胶囊的制备工艺稳定可行。     

Azéma martingales for Bessel and CIR processes and the pricing of Parisian zero‐coupon bonds

In this paper, we study the excursions of Bessel and Cox–Ingersoll–Ross (CIR) processes with dimensions . We obtain densities for the last passage times and meanders of the processes. Using these results, we prove a variation of the Azéma martingale for the Bessel and CIR processes based on excursion theory. Furthermore, we study their Parisian excursions, and generalize previous results on the Parisian stopping time of Brownian motion to that of the Bessel and CIR processes. We obtain explicit formulas and asymptotic results for the densities of the Parisian stopping times, and develop exact simulation algorithms to sample the Parisian stopping times of Bessel and CIR processes. We introduce a new type of bond, the zero‐coupon Parisian bond. The buyer of such a bond is betting against zero interest rates, while the seller is effectively hedging against a period where interest rates fluctuate around 0. Using our results, we propose two methods for pricing these bonds and provide numerical examples.     

Competition‐driven repositioning

We study competition as an impetus for firms to reposition—to abandon their current positioning strategy and adopt a new one. We predict that as a strong firm moves closer, competition erodes the profitability of situated firms and prompts them to reposition. We expect this effect is pronounced the greater difference in competitive strength. However, we expect that countervailing forces exist such that the viability of alternative positions and the opportunity cost of abandoning a current position mitigate this effect. Evidence from a natural experiment in China's satellite television industry supports our hypotheses. This research adds to the existing literature on repositioning, which emphasizes the phenomenon as opportunity‐driven, and to the competitive interaction literature, which typically does not distinguish between noncounterattack strategies. Copyright © 2013 John Wiley & Sons, Ltd.     

Determinants of consumer demand for circular economy products. A case for reuse and remanufacturing for sustainable development

We investigate determinants of consumer demand for circular (reused and remanufactured) products. Based on exploratory choice-based conjoint experiments with a sample of 800 adults in the United Kingdom, we examine two types of premium segment electronic appliances: a mobile phone and a robot vacuum cleaner. We find that consumers prefer partly circulated products over fully or not at all circulated products and that circular products can likely successfully enter the existing market at the retail price of a new product. Interestingly, circular products compete for market share primarily with new products, leaving the market share of second-hand options less affected. The results show a promising path for firms considering a transition to circular business models.     

Study of emerging air taxi network operation using discrete-event systems simulation approach

This research focuses on understanding the air taxi operations to determine the number of air taxis required to fulfill the demand for urban air mobility in New York City (NYC). We leverage the Define, Measure, Analyze, Design, and Verify (DMADV) framework and integrate it with the systems simulation approach. Upon investigation, we find that all the parameters linearly impact the vehicle utilization, while other measures are robust, specifically with respect to the seating capacity. It is also recommended to operate initially with 70 air taxis in NYC to achieve a trade-off between customer wait time and vehicle utilization. The proposed approach can act as a recommender system for air taxi companies.