Rising South, shrinking North: Paradoxically increased unevenness in the global urban economic system

The urban economy, a more definitive indicator of city size than merely the urban population, encompasses both the population and per capita gross domestic product (GDP). This study employs nighttime light imagery to identify the scopes of 11,946 cities worldwide. For the first time, it evaluates the trend of evenness in the global urban economic system (UES) over the past three decades. The finding reveals an increased unevenness in the global UES, with the top 20% of cities accounting for approximately 80% of the global GDP. Moreover, there is a significant regional disparity in the city rank changes within the global UES. In Asia , many cities have significantly raised their ranks, while most cities in Europe and North America show the opposite trend. Among developing countries globally, the number of cities in the top 20% grew at a rate of 30.29%, while the number of cities in the top 20% of developed countries declined by 23.75%. Despite the significant economic growth of some developing cities (mainly in Africa and Asia), it has not mitigated the trend of increasing unevenness in the global UES.