ABSTRACT

Taylor’s law states that the variance of population density in a given set of areas is a power function of its mean. When the exponent is equal to 2, the distribution of population densities between areas remains unchanged; when it is less than 2, the distribution converges toward the uniform distribution; when it is greater than 2, the densities become increasingly different from each other over time. The exponent takes the value 2 for East Asia, the Pacific, and South Asia. It takes a value greater than 2 for sub-Saharan Africa because the ongoing demographic transition and intense urbanization are redistributing the population over the territories. The exponent is lower than 2 for the other regions of the world, which have completed their demographic transition and where the rural exodus has been completed.

摘要

泰勒定律指出，给定区域中人口密度的方差是其均值的幂函数。当指数等于2时，区域间人口密度分布保持不变；当小于 2 时，分布趋于均匀分布；当它大于 2 时，密度随着时间的推移变得越来越不同。东亚、太平洋和南亚的指数取值为 2。对于撒哈拉以南非洲，它的值大于 2，因为持续的人口转变和强烈的城市化正在重新分配这些地区的人口。世界其他地区的指数低于 2，这些地区已经完成了人口转变和农村人口外流。