Simulating non‐normal distributions with specified L‐moments and L‐correlations

This paper derives a procedure for simulating continuous non‐normal distributions with specified L‐moments and L‐correlations in the context of power method polynomials of order three. It is demonstrated that the proposed procedure has computational advantages over the traditional product‐moment procedure in terms of solving for intermediate correlations. Simulation results also demonstrate that the proposed L‐moment‐based procedure is an attractive alternative to the traditional procedure when distributions with more severe departures from normality are considered. Specifically, estimates of L‐skew and L‐kurtosis are superior to the conventional estimates of skew and kurtosis in terms of both relative bias and relative standard error. Further, the L‐correlation also demonstrated to be less biased and more stable than the Pearson correlation. It is also shown how the proposed L‐moment‐based procedure can be extended to the larger class of power method distributions associated with polynomials of order five.     

Measuring CPI's reliability: the stochastic approach to index numbers revisited

The reliability measurement of the Consumer Price Index (CPI) has recently drawn much attention, as the index number has been criticized for its inaccuracy in accessing the degree of inflation. This article centers on providing a new regression specification that can help better gauge the CPI's reliability. More specifically, based on the stochastic approach to index numbers, we argue that the conventional treatment of the systematic changes in relative prices should be made time variant. We therefore propose a more comprehensive regression specification by including additional dummies that represent different general inflation rate levels and business cycle phases. Under this framework, we are more capable of avoiding possible misspecifications in the regression equation, as was experienced by Clements and Izan (1987). It also allows us to better answer the ‘Keynes’ critic’ regarding the stochastic approach to index numbers. The empirical results of Australia and the US are used to validate the merit of our specification.     

Do sunspot numbers cause global temperatures? Evidence from a frequency domain causality test

This article applies the causality test in the frequency domain, developed by Breitung and Candelon (2006), to analyse whether sunspot numbers (used as a partial approximation to solar irradiance) cause global temperatures, using monthly data covering the time period 1880:1–2013:9. While standard time domain Granger causality test fails to reject the null hypothesis that sunspot numbers do not cause global temperatures for both full and sub-samples (identified based on tests of structural breaks), the frequency domain causality test detects predictability for both the full-sample and the last sub-sample at short (2–2.6 months) and long (10.3 months and above) cycle lengths, respectively. Our results highlight the importance of analysing causality using the frequency domain test, which, unlike the time domain Granger causality test, allows us to decompose causality by different time horizons, and hence, could detect predictability at certain cycle lengths even when the time domain causality test might fail to pick up any causality. Further, given the widespread discussion in the literature, those results for the full-sample causality, irrespective of whether it is in time or frequency domains, cannot be relied upon when there are structural breaks present, and one needs to draw inference regarding causality from the sub-samples, we can conclude that there has been an emergence of causality running from sunspot numbers to global temperatures only recently at cycle length of 10.3 months and above.     

Assessment of alternative railway systems for sustainable transportation using an integrated IRN SWARA and IRN CoCoSo model

The long-term sustainability of the railway transportation system is determined by a set of criteria that must be considered. For this reason, multi-criteria decision-making (MCDM) techniques have been used because of their high possibility of providing complementary instruments with successful flexibility. Keeping this in mind, we developed a multi-criteria method to conduct an assessment of currently operational railway systems in West Africa for sustainable transportation based on the examination of key challenges affecting the railway system. This study presents the interval rough step-wise weight assessment ratio analysis-combined compromise solution (IR-SWARA-CoCoSo) model. We have adapted the model to group decision-making by incorporating a new technique for dealing with ambiguity and the utilization of interval rough numbers (IRNs). To evaluate the importance coefficients of criteria in the group decision-making procedure, a new interval rough SWARA method has been introduced as an improvement to handle the issues related to MCDM. For the evaluation of the railway transportation system for sustainable transportation, a novel interval rough CoCoSo method was used. According to the findings, information systems is the most critical challenge to the railway transportation system, while the railway system in Nigeria is the best among others. The results were validated in two stages of sensitivity analysis: a comparison with different interval rough approaches, and the calculation of Spearman's correlation coefficient and WS coefficient for all ranks in the comparative analysis.     

基于三角模糊数的应急物资储备能力综合评价研究

近年来,随着突发事件的频发,对应急物流运作水平要求越来越高,而应急物资储备能力的构建是其中的关键环节。通过文献调查法、样卷调查法,分析了影响应急物资储备能力的因素,构建了相应指标体系。然后运用三角模糊数理论建立了与应急物资储备特性高度吻合的应急物资储备能力评价模型。最后实证研究表明,该方法既体现评价的客观性、针对性,又充分体现应急物资储备能力评价模糊性,使评价结果更加科学合理。     

基于三角模糊层次分析的电子商务物流项目评价研究

对申请进入物流园区的项目进行科学评价和筛选．是确保因区物流项目质量的重要手段。针对目前电子商务物流飞速发展的现状,结合电子商务物流的特点。构建适用于电子商务物流项目的评价指标体系,采用层次分析法确定各因素权重．并结合三角模糊数理论对项目进行综合评价打分。通过实证分析说明该三角模糊数评价模型能够有效评价电子商务物流项目。     

Index Number Concepts,Measures and Decompositions of Productivity Growth

This paper explores the definitions and properties of total factor productivity growth (TFPG) indexes, focusing especially on the Paasche, Laspeyres, Fisher, Törnqvist, and implicit Törnqvist ones. These indexes can be evaluated from observable price and quantity data, and certain of these are shown to be measures of TFPG concepts and theoretical indexes that have been proposed in the literature. The mathematical relationships between these and quantity aggregates, financial measures, and price and quantity indexes are explored. Decompositions of the productivity growth indexes are also given. The paper concludes with a brief overview of some limitations on our analysis.     

A Method for Transitive and Additive Multilateral Comparisons: A Transitive Bennet Indicator

It is shown how the Bennet indicator (or ``index') can be made transitive. This is particular useful for making consistent (profit, cost, price, quantity) comparisons between firms when there are more than two firms and/or more than two periods. The method is given both statistical and economic justifications.     

Pierson on scarcity of gold and changes in the general price level

This paper is a historical reflection on the monetary view of Pierson. (1838–1910) a nineteenth-century Dutch economist, Bank president and prime minister, and his writing on the appropriateness of index numbers to measure inflation. Two aspects are conisdered. First, a policy of price stability should not focus solely on a general price index because this does not take inot account monetary factors sufficiently. Second, a pure monetary explanation as in the gold debate of the 1880s falls short of the mark and might conceal what really is going on, e.g. deflation.