Inference in Arch and Garch Models with Heavy–Tailed Errors

ARCH and GARCH models directly address the dependency of conditional second moments, and have proved particularly valuable in modelling processes where a relatively large degree of fluctuation is present. These include financial time series, which can be particularly heavy tailed. However, little is known about properties of ARCH or GARCH models in the heavy–tailed setting, and no methods are available for approximating the distributions of parameter estimators there. In this paper we show that, for heavy–tailed errors, the asymptotic distributions of quasi–maximum likelihood parameter estimators in ARCH and GARCH models are nonnormal, and are particularly difficult to estimate directly using standard parametric methods. Standard bootstrap methods also fail to produce consistent estimators. To overcome these problems we develop percentile–t, subsample bootstrap approximations to estimator distributions. Studentizing is employed to approximate scale, and the subsample bootstrap is used to estimate shape. The good performance of this approach is demonstrated both theoretically and numerically.     

稳定型机构投资者、盈余平滑与股价同步性

稳定型机构投资者秉承长期投资和价值投资理念,在提高上市公司信息披露质量、增强资本市场韧性等方面能够发挥重要作用。基于2010—2021年中国沪深A股上市公司数据,以盈余平滑为会计信息质量的衡量维度,考察了稳定型机构投资者对不同属性盈余平滑的影响,并探讨了其在降低股价同步性方面的治理作用。研究发现:稳定型机构投资者可以促进企业的信息属性盈余平滑,抑制机会主义属性盈余平滑；稳定型机构投资者通过促进信息属性盈余平滑降低了资本市场的股价同步性；异质性分析表明,当企业内部控制较差、市场竞争程度较高时,稳定型机构投资者对信息属性盈余平滑的促进作用更大。因此,要加快建设机构投资者体系,发挥稳定型机构投资者提高企业会计信息质量的积极作用,以提升资本市场资源配置效率,推动资本市场高质量发展。     

Public perceptions of castle doctrine and stand your ground cases

Introduction

Stand your ground (SYG) and castle doctrine (CD) laws are presently growing throughout the United States. The present study aims to better understand public perceptions of SYG and CD cases and demographic factors that influence judicial decision making.

Methods

Participants were 204 adults who were randomly assigned one of four vignettes that depicted a CD or SYG scenario and varied by defendant demographics. After reading the vignette, participants completed a questionnaire assessing whether they believed the defendant was guilty of the murder and whether the homicide was justified.

Results

Results indicated participants were more likely to assign a guilty verdict to the SYG scenario, compared to the CD scenario. Additionally, participants assigned to the SYG vignette believed the male defendant was more justified in killing the victim, compared to participants assigned the female defendant.

Conclusion

Results from this study reveal how potential jurors may harbor sex/gender bias in determining justifiable homicide in stand your ground cases.