Assurance payments on the coordination of threshold public goods provision: An experimental investigation

We investigate the assurance payment mechanism (APM) in a single-unit threshold public good game. APM offers an assurance payment ($AP$) as compensation to would-be contributors if the group fails to provide the good and individual contributions reach a pre-determined price. We characterize the set of pure-strategy Nash equilibria for APM under complete information and show that assurance payments substantially reduce the multiplicity of equilibria and eliminate the set of non-provision equilibria in a general setup. We find strong evidence that APM improves upon the baseline provision point mechanism without assurance in lab experiments. Assurance payments act as a coordination device and induce more contributions concentrated on $AP$, especially for agents with values above $AP$, leading to more frequent successful provision, higher group contributions, and an overall welfare improvement. Our experimental findings highlight the non-equilibrium mis-coordination as the main reason for the non-provision of threshold public goods and indicate that the format of assurance payments plays a key role in successful coordination even when provision is the unique equilibrium outcome.     

中国五大城市群R&D资本存量差异与分布特征

使用Dagum基尼系数、描述性统计等方法，研究中国五大城市群R&D资本存量差异与分布特征。结果显示：中国五大城市群R&D资本存量差异大，但呈缓慢下降趋势，差异主要来源于不同城市群之间；不同城市群内部以及不同城市群之间R&D资本存量差异大小及其演进趋势具有显著差异。R&D资本存量向五大城市群特别是长三角城市群以及粤港澳大湾区集聚。五大城市群内部R&D资本存量分布特点及演进趋势各不相同。鉴于此，揭示了中国五大城市群R&D资本存量差异与分布特征，从而为城市创新发展战略及政策制定提供理论依据。     

The trend premium around the world: Evidence from the stock market

This paper studies the predictive power of the trend strategy in the international stock market. Using data from 49 markets, we find that a trend signal exploiting the short-, intermediate-, and long-term price information can predict stock returns cross-sectionally in the international market. The significance of the trend strategy is associated with market-level characteristics such as macroeconomic conditions, culture, and the information environment. The trend premium is more pronounced in markets with a more advanced macroeconomic status, a higher level of information uncertainty and individualism, and better accessibility to foreign investors. Nevertheless, the trend strategy only outperforms the momentum strategy in a relatively short horizon.     

一种大倾斜相机影像全自动无缝镶嵌方法

航空长焦距倾斜相机在高空拍摄地物成像的时候具有倾角大、分辨率高、重叠区域广的特点.通过对多幅大倾斜图像的绝对定向、相对定向、影像匀色、拼接缝搜索和消除等问题进行分析,建立了航空长焦距倾斜相机影像全自动无缝镶嵌流程,并进行了试验验证.实验表明,自动无缝镶嵌结果满足定位精度既定要求,该流程设计具有很高的实用价值.     

收入不平等下的零加成改革*——医生策略反应与医疗支出再分配

本文主要研究药品零加成改革引起的医疗支出在病情间的再分配效应。首先，本文利用中国健康与养老追踪调查进行双重差分分析，讨论改革对医疗支出在病情间分配的影响。回归结果显示，地区平均药占比每增加10个百分点，病情严重程度等于均值的患者的总治疗费用将显著上升513%。在此基础上，病情严重程度每增加1个标准差，患者的总治疗费用将少增加298%。进一步，本文在患者收入、病情二维异质性的框架下讨论了这种现象可能的成因并从实证上进行验证。分析表明，改革提高了对重症更有益的诊疗手段的相对价格，改变了医生在诊疗方案上的选择。这种改变会因患者的支付能力不同而有差异，相比收入低且病情较重的患者，医生更多地对收入高且病情较轻的患者使用了对重症更有益的诊疗手段。这种微观选择引起了医疗资源在病情间的扭曲配置和医疗支出向轻病的倾斜。     

阵列处理器中改进几乎空白子帧算法的并行化实现

两层异构网络中出现的小区间干扰协调是当前异构网络干扰问题研究的热点。针对软件实现增强小区调度几乎空白子帧(ABS)的干扰方案存在处理数据量大、速度慢的缺点，基于可重构阵列结构提出了一种动态ABS干扰协调的并行化硬件实现方案。该算法在增强小区内根据用户数动态分配ABS比例，以改善小区边缘用户的信道容量，通过流水线的方式使用多个轻核处理元(PE)实现并行计算以提高运算效率。测试结果表明，使用12个PE同时调度实现算法的映射，运行1 983个周期，其性能比单个PE提升77.03%，该算法的并行计算能力得到显著提升，宏基站用户的吞吐量可以达到4.76 Mbit/s。     

基于遗传算法的测量船工况优选方法

根据传统工况设计方法中存在的约束条件多、计算量大、主观因素影响大等特点,采用过滤函数、适应度评估、位串编码、轮盘选择等方法,提出了一种基于遗传算法的测量船工况优选方法,并分析了收敛速度、终止条件、基因突变等影响因素.实验表明,此方法有效提高了测量船工况设计客观性和设计效率,优选了设计结果.