Local Powers of Optimal One‐sample and Multi‐sample Tests for the Concentration of Fisher‐von Mises‐Langevin Distributions

One‐sample and multi‐sample tests on the concentration parameter of Fisher‐von Mises‐Langevin distributions on (hyper‐)spheres have been well studied in the literature. However, only little is known about their behaviour under local alternatives, which is due to complications inherent to the curved nature of the parameter space. The aim of the present paper therefore consists in filling that gap by having recourse to the Le Cam methodology, which has recently been adapted from the linear to the spherical setup. We obtain explicit expressions of the powers for the most efficient one‐ and multi‐sample tests. As a nice by‐product, we are also able to write down the powers (against local Fisher‐von Mises‐Langevin alternatives) of the celebrated Rayleigh test of uniformity. A Monte Carlo simulation study confirms our theoretical findings and shows the empirical powers of the above‐mentioned procedures.     

Environmental–Economic Accounting: Progress and Digression in the SEEA Revisions

The 1992 Earth Summit and its message of sustainable development drove the launching of a System for integrated Environmental and Economic Accounting, the SEEA. Since then, sustainable development and the SEEA have given way to green growth and green economy indicators in the latest 2012 Summit. A lengthy revision process has now produced a curtailed “SEEA central framework.” The new framework focuses on expenditures for environmental protection and resource management, and stocks and flows of “economic” resources; both are covered by the conventional national accounts. Environmental degradation, notably from pollution, is left to “experimental” ecosystem accounts. Further revision of the SEEA should reverse this retrenchment from integrative environmental–economic accounting. A comprehensive satellite system, rather than a limited statistical standard, might put the SEEA back on the policy agenda.     

Socio-economic and biophysical determinants of land degradation in Vietnam: An integrated causal analysis at the national level

Recognizing the socio-economic and biophysical causes of land degradation at the national level is important for cause-targeted strategies when designing policies for combating land degradation. This study aims to identify the biophysical and socio-economic factors that significantly affect land degradation across Vietnam and to interpret the causalities underlying the effects. The dependent variables considered in the study are spatial, the extent and intensity of degradation in three land-use zones (agriculture, forest and severely degraded abandonment). The hypothesized explanatory variables are common economic and demographic drivers and bio-physical factors such as soil, terrain constraints, and neighborhood land-use structures that are often neglected in many large-scale land degradation assessments. Instead of using a single inferential statistic technique, we used multi-linear regression and binary logistic regression in a complementary manner to increase the detectability and credibility of the degradation cause analyses. The results showed agricultural production growth had strong and consistent effects on land degradation extent and intensity. Population growth, especially in rural areas, had a strong effect on the extent of overall land degradation. The importance of a neighboring forest was revealed for its ability to reduce land degradation intensity in abandoned, unproductive lands. The concrete faceting of the causal analysis for each land-use zone as social–ecological stratum allowed us to combine the defined social–ecological contexts, contemporary theories, and hypotheses in the field to clarify the causal factors of a complex phenomenon like land degradation. The study demonstrates these contemporary inferential statistics can be complementarily used to sufficiently detect and understand land degradation causes at the national level. The results suggest implications for national land management policy: internalizing land degradation costs in the farming system evaluation for payment for ecosystem services policy, restricting forest conversion, and improving extension services and education in agrarian communities.     

Applications of Statistics in the Field of General Insurance: An Overview

This is an expository paper on applications of statistics in the field of general insurance, also called non‐life insurance. Unlike life insurance where advanced statistical techniques have long been part of financial mathematics and actuarial applications, their use is only relatively recent in non‐life insurance. The business model of insurance companies, especially those active in non‐life insurance, has seen dramatic changes over the last 15 years. The aim of this paper is to convince the readers that especially today non‐life insurance is not only an exciting ground to apply existing modern statistical tools but also a fertile environment for new and challenging statistical developments. The activities of an insurance company can be viewed as an industrial process where data management and data analysis play a key role. That is why a fundamental understanding of data‐related issues (such as data quality, variability, analysis and correct interpretation) is so essential to the insurance business. These are exactly the tasks where professional statisticians excel. Also, a better understanding of the field of general insurance by statisticians will promote fruitful exchanges between actuaries and statisticians, thereby helping to bring actuarial and statistical professional societies closer to each other. Selected examples are used to cover the essential aspects of general insurance, and all of them are based on the author's experience. The paper concludes with some remarks on the role of statisticians working in general insurance.     

大数据对法院司法统计的积极功效及边界

最高人民法院于2016年应用人民法院大数据管理和服务平台以后,全国法院司法统计完全实现计算机自动采集。从发展脉络来看法院司法统计正处于智能化转型阶段,仍然存在一些问题。随着大数据及新技术的引入,司法统计“大数据”得以成为现实,包括了数据采集的全面化、统计分析的综合化、统计平台的社会化,进而提出了大数据助力司法统计精准化的具体路径,包括了提高基础数据的量与质、加强对司法统计数据的深度分析和可视化分析、推进基础设施建设。然而,二者并不具有正相关性。因此,推进司法统计大数据化需要注意有两个限度。     

THE GINI CONCENTRATION INDEX: A REVIEW OF THE INFERENCE LITERATURE

More than a century ago, Corrado Gini proposed his well-known concentration index for measuring the degree of inequality in the distribution of income and wealth. His index is still extremely relevant and widely used in several fields of research and application. In this paper, we focus on the inferential properties of the Gini index, and discuss the main directions of analysis proposed in the literature. The aim of the paper is to provide a comprehensive review of the main developments on the inferential aspects of the Gini concentration ratio. We feel that this work can provide a valuable contribution to those scholars who are approaching the large amount of literature on the inferential properties of the Gini index.     

Identifying micro-destinations and providing statistical information: a pilot study in the Canary Islands

Municipalities and regions are often used as an object of tourism analysis at the subnational level. This occurs because administrative borders are used to implement tourism policies and collect statistical information. However, administrative boundaries may not always be suitable for studying tourism destinations at a local level. Sometimes, particularly in high-density tourism destinations, several differentiated tourism areas occupy a single municipality; tourism areas may, and often do, extend beyond municipal boundaries and tourism destinations may not occupy the whole of the municipal area. As such, a new level of analysis is often required: the micro-destination. There are few tourism concepts as imprecise as that of the destination. Therefore, the process of identifying and establishing the boundaries of a micro-destination is by no means a straightforward one. This paper presents six criteria for establishing the boundaries of this type of tourism area. Of these six, the two primary criteria used are: the concentration of tourism establishments; and tourism typologies and supply characteristics. These criteria have been applied as part of a pilot study in the Canary Islands. Statistical information for nine micro-destinations is generated using the geolocation of tourism establishments together with information obtained from both supply-side and demand-side surveys.     

Asymptotic comparison at optimal levels of reduced‐bias extreme value index estimators

In this article we are interested in the asymptotic comparison, at optimal levels, of a set of semi‐parametric reduced‐bias extreme value (EV) index estimators, valid for a wide class of heavy‐tailed models, underlying the available data. Again, as in the classical case, there is not any estimator that can always dominate the alternatives, but interesting clear‐cut patterns are found. Consequently, and in practice, a suitable choice of a set of EV index estimators will jointly enable us to better estimate the EV index γ, the primary parameter of extreme events.     

New insights into an old problem – enhancing student learning outcomes in an introductory statistics course

Many students enrolled in first year introductory statistics courses believe learning statistics is a waste of time and fear they will fail. In this study, we explored the impacts on learning outcomes for students in an introductory statistics course by allowing students to arbitrarily choose their own sequence of learning from three key learning activities, namely tutorials, Peer-Assisted Study Sessions and Computer-Managed Learning quizzes. Unlike the old regime where the learning activities followed a strict, rigid sequence, a new regime allowed students to freely choose when, where and how they engaged with the course learning activities. This allowed increased opportunities for students to receive relevant and timely feedback. Using a total of 1187 students enrolled in semester 2 of 2011, 2012 and 2013, data were collected on students’ scores from 7 assessment tasks. Our experimental design ensured as many course features as possible remained constant between the control cohorts (of 2011 and 2012) and the experimental cohort (2013), thereby avoiding potential sample selection problems. The findings showed student learning outcomes in the new regime improved significantly. Interestingly, the effects were found to be greatest in the lower percentile of the score distribution.     

Variation diminishing property of densities of uniform generalized order statistics

Let f _*,r , r ≥ 1, denote the density function of rth uniform generalized order statistics as defined by Kamps (1995) or Cramer and Kamps (2003). We prove the following variation diminishing property: the number of zeros in (0,1) of any linear combination does not exceed the number of sign changes in the sequence (a ₁, . . . ,a _r ). This result is applied to study monotonicity and convexity properties of f _*,r .