Cities have been considered centers of wealth and opportunity. These are places where the affluent thrive and the common folks find better livelihoods. However, behind their glimmer, cities are also known for demonstrating the widening gap between the rich and the poor. Researchers at the Max Planck Institute for Geoanthropology, drawing data from ancient Roman and modern cities, found a relationship between urban growth or increase in population size and growing socioeconomic inequality.
Bigger Cities, Bigger Divides: Study Shows that Population Size and the Wealth of the Elites are Related
The Growth of Cities and Wealth
The development of cities dates back to early civilizations when humans transitioned from nomadic lifestyles to settled communities. The growth of agriculture allowed populations to expand. This leads to the establishment of permanent settlements. Over time, these settlements evolved into cities, becoming hubs of trade, governance, and culture.
It is also worth mentioning that the expansion of urban centers attracted diverse populations and resulted in the emergence of diversified economic activities. But with this growth came social hierarchies. Wealth and power became concentrated among a disproportionately small group. This pattern of urban development and inequality has persisted throughout history.
A team of researchers headed by W. C. Carleton investigated the connection between urban population size and elite wealth. Researchers analyzed data from ancient Roman cities and compared it with modern cities. They examined physical markers of elite wealth. These include monuments in ancient cities and skyscrapers in modern cities.
However, it is also important to note that the increase follows a sublinear pattern, meaning that while elite wealth rises with city size, each additional increase in population results in a slightly smaller rise in elite wealth. This suggests that although larger cities generate more wealth, the accumulation of elite wealth does not keep pace with the overall growth.
Understanding the Methodology
The study gathers evidence from two distinct periods and applies a comparative approach to examine the relationship between urban population size and elite wealth. The study assumes that both ancient monuments and modern skyscrapers represent physical manifestations of elite wealth. Take note of the following:
• Ancient Rome: Number of monuments and inscriptions dedicated to elite patrons were used as indicators of wealth concentration. Archaeological data from well-documented Roman cities were analyzed.
• Modern Cities: Number of very tall buildings and skyscrapers was used as a proxy for elite wealth. The number of billionaires per city also served as another measure of extreme wealth concentration.
Moreover, to address uncertainties in archaeological and historical data, Bayesian statistical modeling was applied. This allowed for probabilistic reasoning. It is also useful when dealing with incomplete or uncertain data. Bayesian inference helps refine estimates of population size and wealth distribution by incorporating prior knowledge and updating it with new data.
The researchers also used agent-based modeling to simulate social and economic interactions and explain why wealth is concentrated in cities. They further ground their investigation in settlement scaling theory. This suggests that cities tend to become productive and wealthier as they grow larger in terms of population size.
Growing Cities Favor the Wealthy
The study found that as cities grow, elite wealth also increases, but at a slower rate than the overall population. This sublinear scaling pattern means that while urban expansion leads to more wealth, the concentration of elite wealth does not increase proportionally. Instead, each additional increase in population results in a slightly smaller gain in elite wealth.
However, despite this sublinear scaling pattern, the researchers also discovered that inequality is a structural feature of urbanization rather than the result of specific policies or economic systems. Their use of Bayesian statistical models to examine both historical and archaeological data helped in confirming the relationship between city size and elite wealth.
Agent-based network simulations supported the finding. It showed that preferential attachment—where individuals with more resources continue to accumulate more wealth—plays a key role in urban inequality. This mechanism creates a self-reinforcing cycle in which elites benefit the most from city growth while lower-income populations see fewer gains.
Implications for Policymaking
This multi-method approach allowed researchers to uncover deep-rooted urban inequalities and suggest that these patterns are not incidental but fundamental to city life. Inequality is not a mere byproduct of modern economies but a pattern seen across time. The findings highlight the need for innovative policies to create more balanced urban environments.
Note that the findings align with the settlement scaling theory or the view that larger and denser settlements exhibit increasing economic activities. However, based on the results, the study also supports the argument and assumption that inequality is not a result of specific policies or economic conditions but a structural outcome of urbanization itself.
The study challenges the idea that tax reforms alone can address inequality. Policymakers should rethink urban planning to mitigate wealth concentration. This could include understanding further the long-term patterns of socioeconomic inequality and examining historical examples where inequality was controlled while economic growth continued.
FURTHER READING AND REFERENCE
- Carleton, W. C., Elton, H., Miranda, W., Work, I., Safarik, D., Winkelmann, R., Laubichler, M., Renn, J., and Roberts, P. 2025. “Parallel Scaling of Elite Wealth in Ancient Roman and Modern Cities with Implications for Understanding Urban Inequality.” In Nature Cities. Springer Science and Business Media LLC. DOI: 1038/s44284-025-00213-1