A parametric model for income and other size distributions and some extensions

摘要

A parametric probability density for modelling income and other size distributions is presented. The distribution, named the double Pareto-lognormal or dPlN, is derived from a simple stochastic model for the evolution of individual incomes and the fact that the time that such an evolution will have been occurring will vary from individual to individual, and will follow a distribution reflecting the population's age-distribution. The dPlN distribution exhibits power-law (Pareto) behaviour in both tails and when plotted on logarithmic axes, its density exhibits hyperbolic-type behaviour. Good fits are shown for a number of income and earnings distributions. Its use in modelling other size distributions is also mentioned.