“The city as the engine for social change and increasing well-being is one of the truly great triumphs of our amazing ability to form social groups and collectively take advantage of economies of scale.”​

- Geoffrey West

Through the analysis of these urban environments as complex systems, ground-breaking research from the Santa Fe Institute has recently made significant strides in quantifying how cities change as they grow. As population densities grow, non-linearities arise as a result of the exponential increases in social interaction. Despite the incredible complexity of the underlying systems within any city, these non-linearities can be summarised by two key scaling laws.

A population of city increases: 

1

The rates of both positive (GDP, patents, productivity) and negative (crime, suicide, homelessness) socio-economic processes increase superlinearly.

2

The amount of physical infrastructure (roads, electricity, water pipes, internet connection) required to support its population increases sublinearly.

If the population of a city were to double, the research shows that the GDP, number of patents, and productivity (i.e., socio-economic processes) of the city would more than double, but the number of roads, length of water pipes, and power used (physical infrastructure) would less than double.

 

In the face of rapidly expanding urban populations worldwide, digging into this research reveals an ever-increasing challenge. Although cities represent increasing returns to scale in terms of sustainability, the unmanaged

co-location of humans in urban environments also results in superlinearly increasing rates of crime and disease.

How can cities be grown so that these positive effects are emphasised, and the negative results are minimised?