Skewed Reflected Distributions Generated by the Laplace Kernel 1 Introduction
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A New Parameter Estimator for the Generalized Pareto Distribution Under the Peaks Over Threshold Framework
mathematics Article A New Parameter Estimator for the Generalized Pareto Distribution under the Peaks over Threshold Framework Xu Zhao 1,*, Zhongxian Zhang 1, Weihu Cheng 1 and Pengyue Zhang 2 1 College of Applied Sciences, Beijing University of Technology, Beijing 100124, China; [email protected] (Z.Z.); [email protected] (W.C.) 2 Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA; [email protected] * Correspondence: [email protected] Received: 1 April 2019; Accepted: 30 April 2019 ; Published: 7 May 2019 Abstract: Techniques used to analyze exceedances over a high threshold are in great demand for research in economics, environmental science, and other fields. The generalized Pareto distribution (GPD) has been widely used to fit observations exceeding the tail threshold in the peaks over threshold (POT) framework. Parameter estimation and threshold selection are two critical issues for threshold-based GPD inference. In this work, we propose a new GPD-based estimation approach by combining the method of moments and likelihood moment techniques based on the least squares concept, in which the shape and scale parameters of the GPD can be simultaneously estimated. To analyze extreme data, the proposed approach estimates the parameters by minimizing the sum of squared deviations between the theoretical GPD function and its expectation. Additionally, we introduce a recently developed stopping rule to choose the suitable threshold above which the GPD asymptotically fits the exceedances. Simulation studies show that the proposed approach performs better or similar to existing approaches, in terms of bias and the mean square error, in estimating the shape parameter. -
Independent Approximates Enable Closed-Form Estimation of Heavy-Tailed Distributions
Independent Approximates enable closed-form estimation of heavy-tailed distributions Kenric P. Nelson Abstract – Independent Approximates (IAs) are proven to enable a closed-form estimation of heavy-tailed distributions with an analytical density such as the generalized Pareto and Student’s t distributions. A broader proof using convolution of the characteristic function is described for future research. (IAs) are selected from independent, identically distributed samples by partitioning the samples into groups of size n and retaining the median of the samples in those groups which have approximately equal samples. The marginal distribution along the diagonal of equal values has a density proportional to the nth power of the original density. This nth-power-density, which the IAs approximate, has faster tail decay enabling closed-form estimation of its moments and retains a functional relationship with the original density. Computational experiments with between 1000 to 100,000 Student’s t samples are reported for over a range of location, scale, and shape (inverse of degree of freedom) parameters. IA pairs are used to estimate the location, IA triplets for the scale, and the geometric mean of the original samples for the shape. With 10,000 samples the relative bias of the parameter estimates is less than 0.01 and a relative precision is less than ±0.1. The theoretical bias is zero for the location and the finite bias for the scale can be subtracted out. The theoretical precision has a finite range when the shape is less than 2 for the location estimate and less than 3/2 for the scale estimate. -
ACTS 4304 FORMULA SUMMARY Lesson 1: Basic Probability Summary of Probability Concepts Probability Functions
ACTS 4304 FORMULA SUMMARY Lesson 1: Basic Probability Summary of Probability Concepts Probability Functions F (x) = P r(X ≤ x) S(x) = 1 − F (x) dF (x) f(x) = dx H(x) = − ln S(x) dH(x) f(x) h(x) = = dx S(x) Functions of random variables Z 1 Expected Value E[g(x)] = g(x)f(x)dx −∞ 0 n n-th raw moment µn = E[X ] n n-th central moment µn = E[(X − µ) ] Variance σ2 = E[(X − µ)2] = E[X2] − µ2 µ µ0 − 3µ0 µ + 2µ3 Skewness γ = 3 = 3 2 1 σ3 σ3 µ µ0 − 4µ0 µ + 6µ0 µ2 − 3µ4 Kurtosis γ = 4 = 4 3 2 2 σ4 σ4 Moment generating function M(t) = E[etX ] Probability generating function P (z) = E[zX ] More concepts • Standard deviation (σ) is positive square root of variance • Coefficient of variation is CV = σ/µ • 100p-th percentile π is any point satisfying F (π−) ≤ p and F (π) ≥ p. If F is continuous, it is the unique point satisfying F (π) = p • Median is 50-th percentile; n-th quartile is 25n-th percentile • Mode is x which maximizes f(x) (n) n (n) • MX (0) = E[X ], where M is the n-th derivative (n) PX (0) • n! = P r(X = n) (n) • PX (1) is the n-th factorial moment of X. Bayes' Theorem P r(BjA)P r(A) P r(AjB) = P r(B) fY (yjx)fX (x) fX (xjy) = fY (y) Law of total probability 2 If Bi is a set of exhaustive (in other words, P r([iBi) = 1) and mutually exclusive (in other words P r(Bi \ Bj) = 0 for i 6= j) events, then for any event A, X X P r(A) = P r(A \ Bi) = P r(Bi)P r(AjBi) i i Correspondingly, for continuous distributions, Z P r(A) = P r(Ajx)f(x)dx Conditional Expectation Formula EX [X] = EY [EX [XjY ]] 3 Lesson 2: Parametric Distributions Forms of probability -
Statistical Distributions in General Insurance Stochastic Processes
Statistical distributions in general insurance stochastic processes by Jan Hendrik Harm Steenkamp Submitted in partial fulfilment of the requirements for the degree Magister Scientiae In the Department of Statistics In the Faculty of Natural & Agricultural Sciences University of Pretoria Pretoria January 2014 © University of Pretoria 1 I, Jan Hendrik Harm Steenkamp declare that the dissertation, which I hereby submit for the degree Magister Scientiae in Mathematical Statistics at the University of Pretoria, is my own work and has not previously been submit- ted for a degree at this or any other tertiary institution. SIGNATURE: DATE: 31 January 2014 © University of Pretoria Summary A general insurance risk model consists of in initial reserve, the premiums collected, the return on investment of these premiums, the claims frequency and the claims sizes. Except for the initial reserve, these components are all stochastic. The assumption of the distributions of the claims sizes is an integral part of the model and can greatly influence decisions on reinsurance agreements and ruin probabilities. An array of parametric distributions are available for use in describing the distribution of claims. The study is focussed on parametric distributions that have positive skewness and are defined for positive real values. The main properties and parameterizations are studied for a number of distribu- tions. Maximum likelihood estimation and method-of-moments estimation are considered as techniques for fitting these distributions. Multivariate nu- merical maximum likelihood estimation algorithms are proposed together with discussions on the efficiency of each of the estimation algorithms based on simulation exercises. These discussions are accompanied with programs developed in SAS PROC IML that can be used to simulate from the var- ious parametric distributions and to fit these parametric distributions to observed data. -
Fixed-K Asymptotic Inference About Tail Properties
Journal of the American Statistical Association ISSN: 0162-1459 (Print) 1537-274X (Online) Journal homepage: http://www.tandfonline.com/loi/uasa20 Fixed-k Asymptotic Inference About Tail Properties Ulrich K. Müller & Yulong Wang To cite this article: Ulrich K. Müller & Yulong Wang (2017) Fixed-k Asymptotic Inference About Tail Properties, Journal of the American Statistical Association, 112:519, 1334-1343, DOI: 10.1080/01621459.2016.1215990 To link to this article: https://doi.org/10.1080/01621459.2016.1215990 Accepted author version posted online: 12 Aug 2016. Published online: 13 Jun 2017. Submit your article to this journal Article views: 206 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=uasa20 JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION , VOL. , NO. , –, Theory and Methods https://doi.org/./.. Fixed-k Asymptotic Inference About Tail Properties Ulrich K. Müller and Yulong Wang Department of Economics, Princeton University, Princeton, NJ ABSTRACT ARTICLE HISTORY We consider inference about tail properties of a distribution from an iid sample, based on extreme value the- Received February ory. All of the numerous previous suggestions rely on asymptotics where eventually, an infinite number of Accepted July observations from the tail behave as predicted by extreme value theory, enabling the consistent estimation KEYWORDS of the key tail index, and the construction of confidence intervals using the delta method or other classic Extreme quantiles; tail approaches. In small samples, however, extreme value theory might well provide good approximations for conditional expectations; only a relatively small number of tail observations. -
Package 'Renext'
Package ‘Renext’ July 4, 2016 Type Package Title Renewal Method for Extreme Values Extrapolation Version 3.1-0 Date 2016-07-01 Author Yves Deville <[email protected]>, IRSN <[email protected]> Maintainer Lise Bardet <[email protected]> Depends R (>= 2.8.0), stats, graphics, evd Imports numDeriv, splines, methods Suggests MASS, ismev, XML Description Peaks Over Threshold (POT) or 'methode du renouvellement'. The distribution for the ex- ceedances can be chosen, and heterogeneous data (including histori- cal data or block data) can be used in a Maximum-Likelihood framework. License GPL (>= 2) LazyData yes NeedsCompilation no Repository CRAN Date/Publication 2016-07-04 20:29:04 R topics documented: Renext-package . .3 anova.Renouv . .5 barplotRenouv . .6 Brest . .8 Brest.years . 10 Brest.years.missing . 11 CV2............................................. 11 CV2.test . 12 Dunkerque . 13 EM.mixexp . 15 expplot . 16 1 2 R topics documented: fgamma . 17 fGEV.MAX . 19 fGPD ............................................ 22 flomax . 24 fmaxlo . 26 fweibull . 29 Garonne . 30 gev2Ren . 32 gof.date . 34 gofExp.test . 37 GPD............................................. 38 gumbel2Ren . 40 Hpoints . 41 ini.mixexp2 . 42 interevt . 43 Jackson . 45 Jackson.test . 46 logLik.Renouv . 47 Lomax . 48 LRExp . 50 LRExp.test . 51 LRGumbel . 53 LRGumbel.test . 54 Maxlo . 55 MixExp2 . 57 mom.mixexp2 . 58 mom2par . 60 NBlevy . 61 OT2MAX . 63 OTjitter . 66 parDeriv . 67 parIni.MAX . 70 pGreenwood1 . 72 plot.Rendata . 73 plot.Renouv . 74 PPplot . 78 predict.Renouv . 79 qStat . 80 readXML . 82 Ren2gev . 84 Ren2gumbel . 85 Renouv . 87 RenouvNoEst . 94 RLlegend . 96 RLpar . 98 RLplot . 99 roundPred . 101 rRendata . 102 Renext-package 3 SandT . 105 skip2noskip . -
Estimation of Pareto Distribution Functions from Samples Contaminated by Measurement Errors
UNIVERSITY of the WESTERN CAPE Estimation of Pareto Distribution Functions from Samples Contaminated by Measurement Errors Lwando Orbet Kondlo A thesis submitted in partial fulfillment of the requirements for the degree of Magister Scientiae in Statistics in the Faculty of Natural Sciences at the University of the Western Cape. Supervisor : Professor Chris Koen March 1, 2010 Keywords Deconvolution Distribution functions Error-Contaminated samples Errors-in-variables Jackknife Maximum likelihood method Measurement errors Nonparametric estimation Pareto distribution ABSTRACT MSc Statistics Thesis, Department of Statistics, University of the Western Cape. Estimation of population distributions, from samples which are contaminated by measurement errors, is a common problem. This study considers the prob- lem of estimating the population distribution of independent random variables Xj, from error-contaminated samples Yj (j = 1, . , n) such that Yj = Xj +j, where is the measurement error, which is assumed independent of X. The measurement error is also assumed to be normally distributed. Since the observed distribution function is a convolution of the error distribution with the true underlying distribution, estimation of the latter is often referred to as a deconvolution problem. A thorough study of the relevant deconvolution literature in statistics is reported. We also deal with the specific case when X is assumed to follow a truncated Pareto form. If observations are subject to Gaussian errors, then the observed Y is distributed as the convolution of the finite-support Pareto and Gaus- sian error distributions. The convolved probability density function (PDF) and cumulative distribution function (CDF) of the finite-support Pareto and Gaussian distributions are derived. The intention is to draw more specific connections between certain deconvolu- tion methods and also to demonstrate the application of the statistical theory of estimation in the presence of measurement error. -
Handbook on Probability Distributions
R powered R-forge project Handbook on probability distributions R-forge distributions Core Team University Year 2009-2010 LATEXpowered Mac OS' TeXShop edited Contents Introduction 4 I Discrete distributions 6 1 Classic discrete distribution 7 2 Not so-common discrete distribution 27 II Continuous distributions 34 3 Finite support distribution 35 4 The Gaussian family 47 5 Exponential distribution and its extensions 56 6 Chi-squared's ditribution and related extensions 75 7 Student and related distributions 84 8 Pareto family 88 9 Logistic distribution and related extensions 108 10 Extrem Value Theory distributions 111 3 4 CONTENTS III Multivariate and generalized distributions 116 11 Generalization of common distributions 117 12 Multivariate distributions 133 13 Misc 135 Conclusion 137 Bibliography 137 A Mathematical tools 141 Introduction This guide is intended to provide a quite exhaustive (at least as I can) view on probability distri- butions. It is constructed in chapters of distribution family with a section for each distribution. Each section focuses on the tryptic: definition - estimation - application. Ultimate bibles for probability distributions are Wimmer & Altmann (1999) which lists 750 univariate discrete distributions and Johnson et al. (1994) which details continuous distributions. In the appendix, we recall the basics of probability distributions as well as \common" mathe- matical functions, cf. section A.2. And for all distribution, we use the following notations • X a random variable following a given distribution, • x a realization of this random variable, • f the density function (if it exists), • F the (cumulative) distribution function, • P (X = k) the mass probability function in k, • M the moment generating function (if it exists), • G the probability generating function (if it exists), • φ the characteristic function (if it exists), Finally all graphics are done the open source statistical software R and its numerous packages available on the Comprehensive R Archive Network (CRAN∗). -
Theoretical Properties of the Weighted Feller-Pareto Distributions." Asian Journal of Mathematics and Applications, 2014: 1-12
CORE Metadata, citation and similar papers at core.ac.uk Provided by Georgia Southern University: Digital Commons@Georgia Southern Georgia Southern University Digital Commons@Georgia Southern Mathematical Sciences Faculty Publications Mathematical Sciences, Department of 2014 Theoretical Properties of the Weighted Feller- Pareto Distributions Oluseyi Odubote Georgia Southern University Broderick O. Oluyede Georgia Southern University, [email protected] Follow this and additional works at: https://digitalcommons.georgiasouthern.edu/math-sci-facpubs Part of the Mathematics Commons Recommended Citation Odubote, Oluseyi, Broderick O. Oluyede. 2014. "Theoretical Properties of the Weighted Feller-Pareto Distributions." Asian Journal of Mathematics and Applications, 2014: 1-12. source: http://scienceasia.asia/index.php/ama/article/view/173/ https://digitalcommons.georgiasouthern.edu/math-sci-facpubs/307 This article is brought to you for free and open access by the Mathematical Sciences, Department of at Digital Commons@Georgia Southern. It has been accepted for inclusion in Mathematical Sciences Faculty Publications by an authorized administrator of Digital Commons@Georgia Southern. For more information, please contact [email protected]. ASIAN JOURNAL OF MATHEMATICS AND APPLICATIONS Volume 2014, Article ID ama0173, 12 pages ISSN 2307-7743 http://scienceasia.asia THEORETICAL PROPERTIES OF THE WEIGHTED FELLER-PARETO AND RELATED DISTRIBUTIONS OLUSEYI ODUBOTE AND BRODERICK O. OLUYEDE Abstract. In this paper, for the first time, a new six-parameter class of distributions called weighted Feller-Pareto (WFP) and related family of distributions is proposed. This new class of distributions contains several other Pareto-type distributions such as length-biased (LB) Pareto, weighted Pareto (WP I, II, III, and IV), and Pareto (P I, II, III, and IV) distributions as special cases. -
Field Guide to Continuous Probability Distributions
Field Guide to Continuous Probability Distributions Gavin E. Crooks v 1.0.0 2019 G. E. Crooks – Field Guide to Probability Distributions v 1.0.0 Copyright © 2010-2019 Gavin E. Crooks ISBN: 978-1-7339381-0-5 http://threeplusone.com/fieldguide Berkeley Institute for Theoretical Sciences (BITS) typeset on 2019-04-10 with XeTeX version 0.99999 fonts: Trump Mediaeval (text), Euler (math) 271828182845904 2 G. E. Crooks – Field Guide to Probability Distributions Preface: The search for GUD A common problem is that of describing the probability distribution of a single, continuous variable. A few distributions, such as the normal and exponential, were discovered in the 1800’s or earlier. But about a century ago the great statistician, Karl Pearson, realized that the known probabil- ity distributions were not sufficient to handle all of the phenomena then under investigation, and set out to create new distributions with useful properties. During the 20th century this process continued with abandon and a vast menagerie of distinct mathematical forms were discovered and invented, investigated, analyzed, rediscovered and renamed, all for the purpose of de- scribing the probability of some interesting variable. There are hundreds of named distributions and synonyms in current usage. The apparent diver- sity is unending and disorienting. Fortunately, the situation is less confused than it might at first appear. Most common, continuous, univariate, unimodal distributions can be orga- nized into a small number of distinct families, which are all special cases of a single Grand Unified Distribution. This compendium details these hun- dred or so simple distributions, their properties and their interrelations. -
A Class of Generalized Beta Distributions, Pareto Power Series and Weibull Power Series
A CLASS OF GENERALIZED BETA DISTRIBUTIONS, PARETO POWER SERIES AND WEIBULL POWER SERIES ALICE LEMOS DE MORAIS Primary advisor: Prof. Audrey Helen M. A. Cysneiros Secondary advisor: Prof. Gauss Moutinho Cordeiro Concentration area: Probability Disserta¸c˜ao submetida como requerimento parcial para obten¸c˜aodo grau de Mestre em Estat´ısticapela Universidade Federal de Pernambuco. Recife, fevereiro de 2009 Morais, Alice Lemos de A class of generalized beta distributions, Pareto power series and Weibull power series / Alice Lemos de Morais - Recife : O Autor, 2009. 103 folhas : il., fig., tab. Dissertação (mestrado) – Universidade Federal de Pernambuco. CCEN. Estatística, 2009. Inclui bibliografia e apêndice. 1. Probabilidade. I. Título. 519.2 CDD (22.ed.) MEI2009-034 Agradecimentos A` minha m˜ae,Marcia, e ao meu pai, Marcos, por serem meus melhores amigos. Agrade¸co pelo apoio `aminha vinda para Recife e pelo apoio financeiro. Agrade¸coaos meus irm˜aos, Daniel, Gabriel e Isadora, bem como a meus primos, Danilo e Vanessa, por divertirem minhas f´erias. A` minha tia Gilma pelo carinho e por pedir `asua amiga, Mirlana, que me acolhesse nos meus primeiros dias no Recife. A` Mirlana por amenizar minha mudan¸cade ambiente fazendo-me sentir em casa durante meus primeiros dias nesta cidade. Agrade¸comuito a ela e a toda sua fam´ılia. A` toda minha fam´ılia e amigos pela despedida de Belo Horizonte e `aS˜aozinha por preparar meu prato predileto, frango ao molho pardo com angu. A` vov´oLuzia e ao vovˆoTunico por toda amizade, carinho e preocupa¸c˜ao, por todo apoio nos meus dias mais dif´ıceis em Recife e pelo apoio financeiro nos momentos que mais precisei. -
Concentration Inequalities from Likelihood Ratio Method
Concentration Inequalities from Likelihood Ratio Method ∗ Xinjia Chen September 2014 Abstract We explore the applications of our previously established likelihood-ratio method for deriving con- centration inequalities for a wide variety of univariate and multivariate distributions. New concentration inequalities for various distributions are developed without the idea of minimizing moment generating functions. Contents 1 Introduction 3 2 Likelihood Ratio Method 4 2.1 GeneralPrinciple.................................... ...... 4 2.2 Construction of Parameterized Distributions . ............. 5 2.2.1 WeightFunction .................................... .. 5 2.2.2 ParameterRestriction .............................. ..... 6 3 Concentration Inequalities for Univariate Distributions 7 3.1 BetaDistribution.................................... ...... 7 3.2 Beta Negative Binomial Distribution . ........ 7 3.3 Beta-Prime Distribution . ....... 8 arXiv:1409.6276v1 [math.ST] 1 Sep 2014 3.4 BorelDistribution ................................... ...... 8 3.5 ConsulDistribution .................................. ...... 8 3.6 GeetaDistribution ................................... ...... 9 3.7 GumbelDistribution.................................. ...... 9 3.8 InverseGammaDistribution. ........ 9 3.9 Inverse Gaussian Distribution . ......... 10 3.10 Lagrangian Logarithmic Distribution . .......... 10 3.11 Lagrangian Negative Binomial Distribution . .......... 10 3.12 Laplace Distribution . ....... 11 ∗The author is afflicted with the Department of Electrical