所得や富の分布とスモールワールドネットワーク上での確率過程(<論文特集>「エコノフィジックス」)  [in Japanese] Income and wealth distribution and stochastic process on small-world networks(<Special Future>Econophysics)  [in Japanese]

We perform empirical study for the personal income and wealth distribution. It is clarified that the high income and wealth follows the Pareto's law (power law distribution) and the low and middle income follows the Gibrat's law (log-normal distribution) under the capitalism. A multiplicative stochastic process is constructed on small-world networks to explain the wealth distribution. Through numerical simulations we show that the reason of a emergence of the Pareto's law and the Gibrat's law consist in the real world networks which is small-world networks.