Skip to content
Surf Wiki
Save to docs
general/continuous-distributions

From Surf Wiki (app.surf) — the open knowledge base

Davis distribution

Probability distribution for income sizes


Probability distribution for income sizes

name =Davis distribution| type =density| pdf_image = | cdf_image = | parameters =b0 scale n 0 shape \mu0 location | support =x\mu | pdf = \frac{ b^n {(x-\mu)}^{-1-n} }{ \left( e^{\frac{b}{x-\mu}} -1 \right) \Gamma(n) \zeta(n) }
Where \Gamma(n) is the Gamma function and \zeta(n) is the Riemann zeta function | cdf =| mean =\begin{cases} \mu + \frac{b\zeta(n-1)}{(n-1)\zeta(n)} & \text{if}\ n2 \ \text{Indeterminate} & \text{otherwise}\ \end{cases} | median = | mode =| variance = \begin{cases} \frac{ b^2 \left( -(n-2){\zeta(n-1)}^2+(n-1)\zeta(n-2)\zeta(n) \right)}{(n-2) {(n-1)}^2 {\zeta(n)}^2} & \text{if}\ n3 \ \text{Indeterminate} & \text{otherwise}\ \end{cases} | skewness =| kurtosis =| entropy =| mgf =| char =|

In statistics, the Davis distributions are a family of continuous probability distributions. It is named after Harold T. Davis (1892–1974), who in 1941 proposed this distribution to model income sizes. (The Theory of Econometrics and Analysis of Economic Time Series). It is a generalization of the Planck's law of radiation from statistical physics.

Definition

The probability density function of the Davis distribution is given by :f(x;\mu,b,n)=\frac{ b^n {(x-\mu)}^{-1-n} }{ \left( e^{\frac{b}{x-\mu}} -1 \right) \Gamma(n) \zeta(n) } where \Gamma(n) is the Gamma function and \zeta(n) is the Riemann zeta function. Here μ, b, and n are parameters of the distribution, and n need not be an integer.

Background

In an attempt to derive an expression that would represent not merely the upper tail of the distribution of income, Davis required an appropriate model with the following properties

  • f(\mu)=0 , for some \mu0 ,
  • A modal income exists
  • For large x, the density behaves like a Pareto distribution: :: f(x) \sim A {(x-\mu)}^{-\alpha-1} , .

Notes

References

References

  1. [[#Kle03. Kleiber 2003]]
Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

Want to explore this topic further?

Ask Mako anything about Davis distribution — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report