Zipf's law in income distribution of companies

Distribution functions of annual income of companies are analyzed based on two company databases. A clear power law distribution consistent with the Z ipf's law can be confirmed for Japanese companies over more than three deca des in income scale. Similar distributions can be confirmed in some other c ountries. It is confirmed that such power laws hold in most of job categori es with slightly modified exponents. An annual income of a company is about two orders of magnitude smaller than its total assets, and the growth rate distribution of income is nearly independent of the income size in contras t to the case of growth rate of assets. (C) 1999 Published by Elsevier Scie nce B.V. All rights reserved.