Income Distribution among Individuals: The effects of economic interactions

Author Name ARATA Yoshiyuki  (University of Tokyo)
Creation Date/NO. May 2013 13-E-042
Research Project Issues Faced by Japan's Economy and Economic Policy Part II: Population decrease, sustained growth, economic welfare
Download / Links


Income distribution (except for very high incomes) is widely understood to be well described by a log-normal distribution. Existing research has modeled an individual's income as an independent stochastic process to explain the observed log-normality. In this paper, I propose a stochastic model whereby an individual's income is not independent, but instead depends crucially on the incomes of other members of the economy. The model clarifies how the effects of economic interactions work. It turns out that they are favorable toward the wealthy as they enable them to keep their status with high probability. This represents a universal structure of economic systems.