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Estimating population coefficient of variation using a single auxiliary variable in simple random sampling

100%
Singh R., Mishra M.
Statistics in Transition new series
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2019
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vol. 20
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issue 4
89-111
EN
This paper proposes an improved estimation method for the population coefficient of variation, which uses information on a single auxiliary variable. The authors derived the expressions for the mean squared error of the proposed estimators up to the first order of approximation. It was demonstrated that the estimators proposed by the authors are more efficient than the existing ones. The results of the study were validated by both empirical and simulation studies.
2
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Comparing particulate matter dispersion in Thailand using the Bayesian Confidence Intervals for ratio of coefficients of variation

88%
Thangjai W., Niwitpong S.
Statistics in Transition new series
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2020
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vol. 21
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issue 5
41-60
XX
Recently, harmful levels of air pollution have been detected in many provinces of Thailand. Particulate matter (PM) contains microscopic solids or liquid droplets that are so small that they can be inhaled and cause serious health problems. A high dispersion of PM is measured by a coefficient of variation of log-normal distribution. Since the log-normal distribution is often used to analyse environmental data such as hazardous dust particle levels and daily rainfall data. These data focus the statistical inference on the coefficient of variation. In this paper, we develop confidence interval estimation for the ratio of coefficients of variation of two log-normal distributions constructed using the Bayesian approach. These confidence intervals were then compared with the existing approaches: method of variance estimates recovery (MOVER), modified MOVER, and approximate fiducial approaches using their coverage probabilities and average lengths via Monte Carlo simulation. The simulation results show that the Bayesian confidence interval performed better than the others in terms of coverage probability and average length. The proposed approach and the existing approaches are illustrated using examples from data set PM10 level and PM2.5 level in the northern Thailand.
3
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ЗАКОНОМЕРНОСТИ ДИФФЕРЕНЦИАЦИИ УСПЕШНОСТИ ВНУТРЕННИХ РЕГИОНОВ СТРАН ЕВРОПЕЙСКОГО СОЮЗА

75%
Komarova V., Selivanova-Fyodorova N., Lonska Y.
Sociālo Zinātņu Vēstnesis
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2020
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issue 1
30-54
EN
The purpose of this article is to study the performance of the internal regions of the EU countries in a broader sense than economic performance. The Human Development Index (HDI) is suitable as a tool for measuring the performance of regions, since its methodology is based on the idea that it is not economic growth in itself, but people and their capabilities that should be determining criteria for assessing the performance of territories. The object of this study is the internal (functional) regions of the EU member states. In turn, the subject of the study is the regularities in the performanceís differentiation of the object of study. To achieve the goal of this article, the authors studied the form and degree of differentiation of the internal regions of the countries of the European Union in terms of their performance measured by the HDI. The study was carried out by checking the correspondence to the Gaussian curve of the distribution of regions according to the probabilities of the average HDI values, as well as by analyzing the degree of differentiation of the internal regions of the European Union countries according to the HDI using the coefficient of variation. The source of empirical information for this study is the database of subnational HDI for the period from 1990 to 2017, created by the Global Data Lab of Radboud University (Netherlands). An analysis of the distribution parameters of the internal regions of the European Union countries (with an emphasis on Latvia and Poland) and the United States (for comparison) on the subnational HDI for the period from 1990 to 2017, as well as an assessment of its [distribution] correspondence to the Gaussian curve, showed that the performanceís differentiation of the internal regions of the EU countries graphically corresponds to the Gaussian curve, i.e. has the form of a normal distribution, while the most successful are almost always the capital regions. In turn, the trajectory of changes in the degree of performance’s differentiation of the internal regions of the countries of the modern EU takes the form of an inverted U-shaped curve, i.e. the differences in the performance of the regions in the territorial space that the EU is now, increased during the last 28 years in the period of collapse of the East European socialist bloc in the early 1990s, and then decreased as the regions adapted to the new conditions of independence and market economy. Thus, the performance’s differentiation of the internal regions of the EU countries over the past three decades was not chaotic, but occurred in accordance with certain regularities empirically proven by the authors for the first time both on an unchanged sample of 278 regions of the EU member states for 2018 and for “cleaned” sample of the internal regions of the EU countries, taking into account the year of their joining the European Union.
4
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Self-reported and market home values in housing wealth inequality measurement: evidence from Warsaw and Prague

75%
Tomal M.
Critical Housing Analysis
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2022
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vol. 9
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issue 1
29-38
EN
This paper aims to examine whether self-reported home valuations can be a substitute for objective market data in studies on the level of housing wealth inequality. In order to achieve this aim, information on subjective values of flats and their features in Warsaw (Poland) and Prague (Czechia) was used. Next, hedonic models were estimated to calculate the objective values of these residential properties. The results indicated that, on average, homeowners overestimated their real estate by 2.10% in Warsaw and underestimated by 5.49% in Prague. Finally, using tests for the equality of variances, it was examined whether the level of housing wealth inequality differed significantly when calculated using subjective and objective home values. The findings showed that self-reported home values cannot serve as a perfect proxy for market values when assessing the level of housing wealth inequality in both cities.
5
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TOPOGRAPHIC CORRECTION OF LAPAN-A3/LAPAN-IPB MULTISPECTRAL IMAGE: A COMPARISON OF FIVE DIFFERENT ALGORITHMS

75%
Zylshal Z.
Quaestiones Geographicae
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2020
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vol. 39
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issue 3
EN
Reflectance variability in mountainous regions caused by steep slopes can decrease the accuracy of landcover mapping. Topographic correction aims to reduce this effect, and various techniques have been proposed to conduct such correction on satellite imagery. This paper presents the initial results of five different topographic correction techniques applied to LAPAN-A3 multispectral images, namely cosine correction, improved cosine correction, Minnaert correction, modified Minnaert correction and two-stage normalization. The widely-available ALOS World 3D 30 meter DEM was employed, with the evaluation made in a mountainous area in South Sulawesi, Indonesia, located in an ancient volcanic region, with slopes ranging from 0 to 60 degrees. The slope aspect was almost equally distributed in all directions. Visual and statistical analysis was conducted before and after the topographic correction to evaluate the results. Standard deviation (SD) and the coefficient variation (CV) were calculated; the results show that the topographic corrections were able to reduce the effect of shadows and relief. Minnaert correction proved to be the best method in terms of visual appearance and spectral variability reduction.
6
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Экономические различия между странами и внутри стран: где они сильнее в XXI веке?

45%
Селиванова-Фёдорова Н., Тутаева Д., Рогова Т.
Sociālo Zinātņu Vēstnesis
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2021
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issue 1
61-77
RU
В научной литературе достаточно много исследований, посвящённых изучению и сравнению экономических различий между странами и между регионами внутри стран в разных макрорегионах мира и в разные периоды времени. Тем не менее, авторы данной статьи не обнаружили среди результатов этих исследований каких-либо эмпирически обоснованных сравнительных выводов об экономических различиях на внешнем межстрановом и внутреннем межрегиональном уровнях. Целью данной статьи является эмпирическая проверка двух популярных в научной литературе гипотез о территориальных экономических различиях в современном мире. Согласно первой гипотезе, экономические различия между странами в современном мире не так велики, как различия между регионами внутри стран. Согласно второй гипотезе, уменьшение экономических различий между странами связано с относительно более быстрым экономическим ростом столичных регионов. В рамках данного исследования измерение экономических различий на различных территориальных уровнях осуществляется методом сравнения коэффициентов вариации доходов населения. Источником эмпирических данных для этого исследования является база данных Субнационального Индекса развития человеческого потенциала (СИРЧП), созданная голландским Институтом управленческих исследований Университета Радбауд, которая содержит показатель доходов населения во внутренних регионах 161 страны мира за период с 2000 по 2018 год. Результаты сравнения динамики экономических различий на разных территориальных уровнях показали, что в течение двух прошедших десятилетий XXI века ни в мире в целом, ни в странах ЕС различия между регионами внутри стран не были выше, чем различия между странами. Однако начиная с 2015 года экономические различия между внутренними регионами стран ЕС стали превышать экономические различия между самими странами, что является отличительной особенностью именно Европейского Союза. В течение всего изучаемого периода XXI века как межстрановые, так и внутренние межрегиональные экономические различия внутри стран ЕС были значительно ниже, чем в мире в целом. Экономическое значение нестоличных регионов – в основном это регионы, расположенные вблизи столиц, т.е. так называемые пристоличные регионы, – в странах ЕС постепенно возрастает, хотя в настоящее время ЕС (и, вероятно, мир в целом) по-прежнему характеризуется экономическим ростом, двигателями которого являются в основном столичные регионы.
EN
In the scientific literature, there are a lot of studies devoted to the investigation and comparison of economic differences between countries and between regions within countries in different macroregions of the world and at different periods of time. However, the authors of the article did not find among the results of these studies any empirically substantiated comparative conclusions about economic differences at the intercountry and internal interregional levels. The purpose of this article is to empirically test two hypotheses popular in the scientific literature about territorial economic differences in the modern world. According to the first hypothesis, economic differences between countries in the modern world are not as large as differences between regions within countries. According to the second hypothesis, the decrease in economic differences between countries is related with relatively faster economic growth in the capital regions. Within this study, the measurement of economic differences at different territorial levels is carried out by comparing coefficients of variation of the populationís income. The source of empirical data for this study is the Sub-national Human Development Index (SHDI) database, created by the Netherlands Institute for Management Research of the Radboud Н. Селиванова-Фёдорова, Д. Тутаева, Т. Рогова. Экономические различия между.. 63 University, which contains indicators of the populationís income in the inner regions of 161 countries of the world for the period from 2000 to 2018. The results of comparing the dynamics of economic differences at different territorial levels showed that over the past two decades of the 21st century, neither in the world as a whole, nor in the EU countries, the differences between regions within countries were no thigher than the differences between countries. However, since 2015, the economic differences between the inner regions of the EU countries began to exceed the economic differences between the countries themselves, which is a distinctive feature of the European Union. During the entire studied period of the 21st century, both inter-country and internal interregional economic differences within the EU countries were significantly lower than in the world as a whole. The economic significance of non-capital regions, which are mainly the regions located near the capitals, i.e. the so-called ěnear-capitalî regions, in the EU countries is gradually increasing, although at present the EU (and, probably, the world as a whole) is still characterized by economic growth, which is based on the growth of capital regions.
LV
Zinātniskajā literatūrā ir daudz pētījumu, kas veltīti ekonomisko atšķirību izpētei un salīdzināšanai starp valstīm un starp reģioniem valstu iekšienē dažādos pasaules makroreģionos un dažādos laika periodos. Tomēr raksta autores šo pētījumu rezultātos neatrada empīriski pamatotus salīdzinošus secinājumus par ekonomiskajām atšķirībām ārējā starpvalstu un iekšējā starpreģionu līmenī. Šī raksta mērķis ir empīriski pārbaudīt divas zinātniskajā literatūra populāras hipotēzes par teritoriālajām ekonomiskajām atšķirībām mūsdienu pasaulē. Saskaņā ar pirmo hipotēzi ekonomiskās atšķirības starp valstīm mūsdienu pasaulē nav tik lielas kā atšķirības starp reģioniem valstu iekšienē. Saskaņā ar otro hipotēzi ekonomisko atšķirību samazināšanās starp valstīm ir saistīta ar relatīvi straujāku ekonomikas izaugsmi galvaspilsētu reģionos. Šī pētījuma ietvaros ekonomisko atšķirību mērīšana dažādos teritoriālajos līmeņos tiek veikta, salīdzinot iedzīvotāju ienākumu variācijas koeficientus. Šī pētījuma empīrisko datu avots ir Radbouda Universitātes Nīderlandes Menedžmenta pētījumu institūta izveidotā Subnacionālā Tautas attīstības indeksa (STAI) datu bāze, kas satur iedzīvotāju ienākumu radītājus 161 valsts iekšējos reģionos laikposmam no 2000. gada līdz 2018. gadam. Ekonomisko atšķirību dinamikas salīdzināšanas rezultāti dažādos teritoriālajos līmeņos parādīja, ka 21. gadsimta divās desmitgadēs ne pasaulē kopumā, ne ES valstīs atšķirības starp reģioniem valstu iekšienē nebija lielākas par atšķirībām starp valstīm. Tomēr kopš 2015. gada ekonomiskās atšķirības starp ES valstu iekšējiem reģioniem sāka pārsniegt ekonomiskās atšķirības starp pašām valstīm, kas ir Eiropas Savienībai raksturīga īpatnība. Visā pētītajā 21. gadsimta periodā gan starpvalstu, gan iekšējās starpreģionu ekonomiskās atšķirības ES valstīs bija ievērojami zemākas nekā pasaulē kopumā. Ne-galvaspilsētu reģionu ekonomiskā nozīme - galvenokārt tie ir reģioni, kas atrodas netālu no galvaspilsētām, t.i., tā saucamie “pie-galvaspilsētas” reģioni - ES valstīs pamazām pieaug, lai gan pašlaik Eiropas Savienībai (un, iespējams, arī visai pasaulei) joprojām ir raksturīga ekonomiskā izaugsme, galvenokārt, uz galvaspilsētu reģionu rēķina.
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