Abstract. The power law or Zipf's law phenomena in human behaviors have been widely observed and attracted intensive attention. In this letter, a new evidence on personal donation is presented and analyzed. A sample of donation to the victims of Sichuan earthquake in 2008 demonstrates that donation distribution has a particular pattern. The upper part is governed by Zipf's law and the lower part exhibits a uniform distribution. We propose a theoretical model in which people's wealth distribution follows a power law, they are willing to donate a random part of their wealth and have preferences on some specific numbers. This model provides us not only a reasonable explanation on the empirical donation pattern but also an effective method to get access to large-scale personal-wealth distributions.

PACS numbers: 89.65.-s, 89.75.Da, 89.65.Gh

Print publication: Issue 3 (November 2009)
Received 30 September 2009, accepted for publication 21 October 2009
Published 4 November 2009