A New Model of Trend Inflation

This article introduces a new model of trend inflation. In contrast to many earlier approaches, which allow for trend inflation to evolve according to a random walk, ours is a bounded model which ensures that trend inflation is constrained to lie in an interval. The bounds of this interval can either be fixed or estimated from the data. Our model also allows for a time-varying degree of persistence in the transitory component of inflation. In an empirical exercise with CPI inflation, we find the model to work well, yielding more sensible measures of trend inflation and forecasting better than popular alternatives such as the unobserved components stochastic volatility model. This article has supplementary materials online.     

A note on the non-negativity of continuous-time ARMA and GARCH processes

A general approach for modeling the volatility process in continuous-time is based on the convolution of a kernel with a non-decreasing Lévy process, which is non-negative if the kernel is non-negative. Within the framework of Continuous-time Auto-Regressive Moving-Average (CARMA) processes, we derive a necessary condition for the kernel to be non-negative, and propose a numerical method for checking the non-negativity of a kernel function. These results can be lifted to solving a similar problem with another approach to modeling volatility via the COntinuous-time Generalized Auto-Regressive Conditional Heteroscedastic (COGARCH) processes.     

An Integrative View of the Institutional Repositories in Hong Kong: Strategies and Challenges

This paper reports on the developmental strategies, challenges and directions of the institutional repositories of the higher educational institutions in Hong Kong. The study integrates the size, content, full text and public accessibility of these repositories. The paper also compares archived output with research output as registered by the Hong Kong University Grants Committee. Percentages of archived work are low for journal and conference papers, but moderate for graduate theses. These deposit rates reflect the differing institutional policies. In recognizing these challenges, the Hong Kong Open Access Committee has been formed to address regional issues in knowledge sharing.     

良治型政府理論與澳門經濟發展

本文從有關良治型政府理論及主要觀點的角度,探討良治型政府理論在澳門的實踐,以及在CEPA框架下澳門政府扮演的經濟角色與可能存在的風險。本文認為應該從增強澳門經濟多元性以及改善制度建設來完善澳門經濟政策。     

负面清单制度的国际经验及其对上海自贸区的启示

负面清单作为上海自贸区改革一大亮点,体现了我国开始着手建立高标准的投资规则。国外的负面清单制度已发展得较为成熟,无论是多边协定NAFTA,或是各双边协定,其负面清单模式都可为上海自贸区的建设提供经验和启示。在上海自贸区负面清单模式推行中,应对重点行业实施重点保护,将负面清单制度化,使经济开放与经济安全相平衡,使宏观经济管理与微观经济自由相平衡,使立法与司法制度相结合。     

台湾社区工作:从“福利小区化”迈向“永续小区”

随着世界小区化服务潮流,自20世纪90年代中期以后,台湾各公共领域之以"小区化"为主轴的服务方案如雨后春笋般的出现."福利小区化"与"小区营造"是其中最获重视的两项计划;经过十余年的推动,"台湾健康小区六星计划"的出现,不仅包含了前两项计划的内容,同时也使小区建设扩展至诸如产业、环境、治安、人文等六个方面;永续小区发展策略在反思以前小区建设经验与问题的基础上出现.检视过去十余年来台湾小区工作发展脉络,特别是从"福利小区化"、"小区营造"到"健康小区六星计划"发展路径,可发现台湾小区工作发展具有多方面借鉴意义;应该从理念、政策和实务多角度省思,以有助于迈向"永续小区".     

Impact of an Overt Response System on Staff Performance and Maintenance of Computer-Based Instruction

Interactive Computer Based Instruction (CBI) systems involve teaching strategies to facilitate greater response opportunities during training in an effort to improve learner performance. The current study investigated the effect of online staff training videos with and without overt response requirements on posttest and maintenance test scores across six block-randomized instructional modules for four employees of a university located in the southeastern region of the United States. The overt response consisted of multiple-choice questions administered throughout select teaching modules using an alternating treatment design. Findings suggest that learning occurred as a result of the CBI training; however, the effectiveness of the overt response system varied across individuals, with no discernible differentiation between learning gains associated with response requirements. Other areas of research for expanding the efficacy of CBI and overt response systems are highlighted.     

New recursive estimators of the time-average variance constant

Estimation of the time-average variance constant (TAVC) of a stationary process plays a fundamental role in statistical inference for the mean of a stochastic process. Wu (2009) proposed an efficient algorithm to recursively compute the TAVC with \(O(1)\) memory and computational complexity. In this paper, we propose two new recursive TAVC estimators that can compute TAVC estimate with \(O(1)\) computational complexity. One of them is uniformly better than Wu’s estimator in terms of asymptotic mean squared error (MSE) at a cost of slightly higher memory complexity. The other preserves the \(O(1)\) memory complexity and is better then Wu’s estimator in most situations. Moreover, the first estimator is nearly optimal in the sense that its asymptotic MSE is \(2^{10/3}3^{-2} \fallingdotseq 1.12\) times that of the optimal off-line TAVC estimator.     

On Bartlett correction of empirical likelihood for regularly spaced spatial data

Bartlett correction constitutes one of the attractive features of empirical likelihood because it enables the construction of confidence regions for parameters with improved coverage probabilities. We study the Bartlett correction of spatial frequency domain empirical likelihood (SFDEL) based on general spectral estimating functions for regularly spaced spatial data. This general formulation can be applied to testing and estimation problems in spatial analysis, for example testing covariance isotropy, testing covariance separability as well as estimating the parameters of spatial covariance models. We show that the SFDEL is Bartlett correctable. In particular, the improvement in coverage accuracies of the Bartlett‐corrected confidence regions depends on the underlying spatial structures. The Canadian Journal of Statistics 47: 455–472; 2019 © 2019 Statistical Society of Canada     

Vegetation on and around large-scale buildings positively influences native tropical bird abundance and bird species richness

High population growth in the tropics is driving urbanisation, removing diverse natural ecosystems. This is causing native species to suffer while introduced synanthropes flourish. City planners are developing urban greenspace networks, in part trying to address this issue. Architects contribute to these greenspace networks by designing elevated and ground level green spaces on large-scale buildings. However, little evidence is available on whether building green spaces support native fauna. This is true for birds in tropical Singapore that support important ecosystem services and have existence value. Therefore, in this study, we conducted bird surveys and statistical analyses to determine, if and how vegetation on three building green space types (ground gardens, roof gardens and green walls) have a positive impact on native or introduced bird species. We found that elevated greenery (roof gardens and green walls) on large-scale buildings supported a higher richness of birds and abundance of urban native birds than control roofs and walls without vegetation. Ground gardens supported similar levels of native species as roof gardens but also a larger proportion of generalist synanthropes. However, we found no tropical forest habitat specialists across any space type. Therefore, we recommend roof gardens and ground gardens as a potential space for urban natives outside of a less competitive ground-level urban environment. Our study also found certain building design elements (height of elevated space, presence of specific plants) supported different species groups. Therefore, we suggest that these ecological requirements for different species groups are considered when designing a building’s green space.