Entrenchment in publicly traded family firms: Evidence from the S&P 500

Family involvement in corporate governance through ownership, management, and board membership presents a unique dilemma for understanding the strategic impetus and costs of entrenchment decisions. The presence of shared family ties and the family-centered goals of firm principals call to question the applicability of extant agency arguments regarding the nature and antecedents of managerial entrenchment. Exploring this, we develop and test a model of family firm-specific determinants (i.e., family ownership and family's involvement in management and governance) of entrenchment in publicly traded firms by drawing upon principal-principal agency theory. Findings of the empirical analysis of family owned S&P 500 firms suggest family firms are motivated to entrench managers when doing so supports the pursuit of family-centric goals. However, the extent to which entrenchment supports such goals varies at different levels of family ownership.     

Heterogeneity in treatment effects across diverse populations

Differences in patient characteristics, including age, sex, and race influence the safety and effectiveness of drugs, biologic products, and medical devices. Here we provide a summary of the topics discussed during the opening panel at the 2018 Johns Hopkins Center for Excellence in Regulatory Science and Innovation symposium on Assessing and Communicating Heterogeneity of Treatment Effects for Patient Subpopulations: Challenges and Opportunities. The goal of this session was to provide a brief overview of FDA-regulated therapeutics, including drugs, biologics and medical devices, and some of the major sources of heterogeneity of treatment effects (HTE) related to patient demographics, such as age, sex and race. The panel discussed the US Food and Drug Administration's role in reviewing and regulating drugs, devices, and biologic products and the challenges associated with ensuring that diverse patient populations benefit from these therapeutics. Ultimately, ensuring diverse demographic inclusion in clinical trials, and designing basic and clinical research studies to account for the intended patient population's age, sex, race, and genetic factors among other characteristics, will lead to better, safer therapies for diverse patient populations.     

人民币汇率失衡及贸易壁垒对我国出口行业影响异质性研究

贸易摩擦、新冠疫情使我国经济贸易面临严峻挑战,人民币汇率波动及贸易壁垒将常态化地影响我国出口贸易.在加快形成以国内大循环为主体、国内国际双循环相互促进的新发展格局背景下,文章基于HS分类原则,选取WTO等机构的贸易数据,通过构建BEER模型测算了人民币汇率失衡程度;通过建立固定效应面板模型研究了人民币汇率失衡及贸易壁垒双因素对我国出口行业影响的异质性.研究表明:人民币汇率失衡对我国出口贸易整体上具有显著负向影响,非关税壁垒对我国出口贸易整体上具有显著正向影响;关税和非关税构成的贸易壁垒与人民币汇率失衡双因素对我国出口贸易具有显著抑制作用,并对不同出口行业的影响存在异质性;人民币汇率失衡与非关税壁垒双因素对大多行业均具有显著负向影响,人民币汇率失衡与关税壁垒双因素对不同行业影响的正负效应及程度大小有异质性.因此,建议通过运行逆周期因子等完善人民币汇率自我修正机制;通过引导出口企业了解使用外汇衍生品等促进外汇衍生品市场运行机制的健全;通过加强"海外仓"建设及深耕RCEP框架下的东盟十国市场等实施出口行业差异化贸易策略;通过提升自主科技创新能力等加快出口行业产业转型升级,推动双循环,实现我国出口贸易高质量发展.     

重庆市县域商品房价格时空变化特征研究——基于空间统计分析法

以2005—2015年重庆市38个区（县）商品房价格数据为样本，利用空间自相关等空间统计分析方法对重庆市县域商品房价格的空间分布和时空演变特征进行研究。研究结果表明：渝东北地区商品房价格稳定性相对最好，渝西地区次之，渝东南地区再次之，主城区商品房价格稳定性最差；重庆市商品房价格具有较强的空间集聚性，但随着时间的推移，空间集聚性逐渐减弱，商品房价格空间差异逐渐缩小；重庆市商品房价格区域差异呈现明显的空间二元结构，房地产发展热点区域主要集中于主城九区，远郊区县的房地产发展相对缓慢。     

‘Show me the money and the party!’ – variation in Facebook and Twitter adoption by politicians

Our study explores the adoption of Facebook and Twitter by candidates in the 2013 German Federal elections. Utilizing data from the German Longitudinal Election Study candidate survey fused with data gathered on the Twitter and Facebook use of candidates, we draw a clear distinction between Facebook and Twitter. We show that adoption of both channels is primarily driven by two factors: party and money. But the impact of each plays out differently for Facebook and Twitter. While the influence of money is homogenous for Facebook and Twitter with the more resources candidates have, the more likely they are to adopt, the effect is stronger for Facebook. Conversely, a party’s impact on adoption is heterogeneous across channels, a pattern we suggest is driven by the different audiences Facebook and Twitter attract. We also find candidates’ personality traits only correlate with Twitter adoption, but their impact is minimal. Our findings demonstrate that social media adoption by politicians is far from homogenous, and that there is a need to differentiate social media channels from one another when exploring motivations for their use.     

竞争环境下的以旧换新策略

企业通过对拥有旧产品的老消费者提供以旧换新补贴能够提升自身销量与利润。然而，面临竞争对手时企业的以旧换新决策是否会受到影响?本文求解了先后进入市场的双寡头竞争企业所面临的以旧换新与定价博弈均衡，并分析了竞争存在与否对于企业以旧换新策略产生的影响。研究结果表明，第一，面对竞争时企业的定价决策受到市场中老消费者比例、两家竞争企业各自新产品的创新提升水平、老产品的使用残值这四个因素的共同影响。第二，当老产品残值相对较低而市场中老消费者数量适中时，两企业均不提供以旧换新可能成为博弈均衡，而其他条件下，两企业均提供以旧换新为博弈均衡。第三，先进入的企业没有动机单独为消费者提供以旧换新补贴。第四，竞争对手的存在对于先进入企业自身的以旧换新决策与相应的定价策略都产生了显著的影响。     

农村人力资本、空间效应与城乡收入差距

基于2000—2017年的省级面板数据,采用SDM模型来研究异质性农村人力资本对城乡收入差距的空间效应,并进一步分解为直接效应和空间溢出效应进行比较分析。结果表明：（1）我国城乡收入差距存在显著正向空间集聚效应,并且这种空间集聚效应与区域经济发展水平紧密相关;（2）初级、中级、高级农村人力资本的空间集聚效应特征呈现明显空间差异：初级农村人力资本大多数集聚于西部省份,中级农村人力资本大多数集聚于现代农业相对发达的省份,而高级农村人力资本的高集聚区经历了从东北地区向长三角地区的动态转移;（3）中级、高级农村人力资本显著缩小了本地区及邻近地区的城乡收入差距,但中级农村人力资本的作用更大,而初级农村人力资本对城乡收入差距的影响不显著。     

Classification with minimum ambiguity under distribution heterogeneity

The traditional classification is based on the assumption that distribution of indicator variable X in one class is homogeneous. However, when data in one class comes from heterogeneous distribution, the likelihood ratio of two classes is not unique. In this paper, we construct the classification via an ambiguity criterion for the case of distribution heterogeneity of X in a single class. The separated historical data in each situation are used to estimate the thresholds respectively. The final boundary is chosen as the maximum and minimum thresholds from all situations. Our approach obtains the minimum ambiguity with a high classification accuracy allowing for a precise decision. In addition, nonparametric estimation of the classification region and theoretical properties are derived. Simulation study and real data analysis are reported to demonstrate the effectiveness of our method.     

考虑异质性行为的灾后应急物资动态调度优化

在以人道主义为本的应急救援活动中，不可忽视被救灾民和施救决策者们异质性行为的影响。一方面，将各灾民因救援物资需求未被及时满足而呈现的差异化心理痛苦度量成经济损失，并纳入应急救援调度的社会成本这一决策目标中；另一方面，在灾后物资调度决策中，关注具有异质性偏好的各应急决策者所展现出的不同救援态度。结合面向联合机会约束规划的动态供需平衡限制，最终构建一个考虑灾民和决策者们异质性行为的多阶段灾后救援物资分配和应急路径优化模型。采用2008年汶川地震为案例背景，应用遗传算法对模型求解和参数分析，将仿真结果与不考虑异质性行为的传统救援调度方案进行比较，得出一些结论为构建高效的应急救援体系提供有益参考。