Scaling of urban income inequality in the USA
Scaling of urban income inequality in the USA
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DOI：
10.1098/rsif.2021.0223
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发表时间：
2021-08-04
影响因子：
3.9
通讯作者：
Kempes, Christopher P.
中科院分区：
文献类型：
--
作者：
Mora, Elisa Heinrich;Heine, Cate;Kempes, Christopher P.
城市尺度分析是研究城市总体特征如何随城市地区人口变化而变化的一项研究，它为发现城市之间的共性和揭示城市在不同时间和空间上共享的动态提供了一个有希望的框架。在这里，我们使用城市尺度框架来研究这种社区收入不平等的一个重要但尚未被探索的特征。本文提出了一种研究收入分配尺度的新方法，即以人口百分位数为单位分析总收入的尺度。我们发现，最不富裕的十分之一（10%）的收入与城市人口呈线性关系，而最富裕的十分之一的收入呈显著的超线性指数。与总收入与城市人口的超线性比例相反，这种十分位数比例表明，大城市的利益分配越来越不平等。对于最贫穷的收入十分之一，城市对线性增长的零预期没有积极影响。我们根据住房成本调整收入后重复我们的分析，发现类似的结果。然后我们进一步分析收入分配的形状。首先，我们发现收入分布的均值、方差、偏度和峰度都随着城市规模的增加而增加。其次，城市收入分配与最大城市收入分配的Kullback-Leibler差异随着城市人口的增加而减小，表明收入分配的整体形态随着城市人口的增加而变化。由于大多数城市尺度理论认为，城市内部相互作用的致密化是导致许多特征超线性增长的基本过程，我们的研究结果表明，这种效应只出现在城市的上层十分位数。我们的发现鼓励未来的工作考虑相互作用的异质模型，以形成对城市规模的更连贯的理解。
Urban scaling analysis, the study of how aggregated urban features vary with the population of an urban area, provides a promising framework for discovering commonalities across cities and uncovering dynamics shared by cities across time and space. Here, we use the urban scaling framework to study an important, but under-explored feature in this community-income inequality. We propose a new method to study the scaling of income distributions by analysing total income scaling in population percentiles. We show that income in the least wealthy decile (10%) scales close to linearly with city population, while income in the most wealthy decile scale with a significantly superlinear exponent. In contrast to the superlinear scaling of total income with city population, this decile scaling illustrates that the benefits of larger cities are increasingly unequally distributed. For the poorest income deciles, cities have no positive effect over the null expectation of a linear increase. We repeat our analysis after adjusting income by housing cost, and find similar results. We then further analyse the shapes of income distributions. First, we find that mean, variance, skewness and kurtosis of income distributions all increase with city size. Second, the Kullback-Leibler divergence between a city's income distribution and that of the largest city decreases with city population, suggesting the overall shape of income distribution shifts with city population. As most urban scaling theories consider densifying interactions within cities as the fundamental process leading to the superlinear increase of many features, our results suggest this effect is only seen in the upper deciles of the cities. Our finding encourages future work to consider heterogeneous models of interactions to form a more coherent understanding of urban scaling.