In order to study the phenomenon in detail that income distribution follows
Pareto law, we analyze the database of high income companies in Japan. We find
a quantitative relation between the average capital of the companies and the
Pareto index. The larger the average capital becomes, the smaller the Pareto
index becomes. From this relation, we can possibly explain that the Pareto
index of company income distribution hardly changes, while the Pareto index of
personal income distribution changes sharply, from a viewpoint of capital (or
means). We also find a quantitative relation between the lower bound of capital
and the typical scale at which Pareto law breaks. The larger the lower bound of
capital becomes, the larger the typical scale becomes. From this result, the
reason there is a (no) typical scale at which Pareto law breaks in the income
distribution can be understood through (no) constraint, such as the lower bound
of capital or means of companies, in the financial system.Comment: 12 pages, 8 figure