How does urbanization concentrate people into cities?

Urbanization is the process by which large numbers of people become permanently concentrated in relatively small areas, forming cities. This concentration is driven by several historical and economic factors:1

• Economic Opportunity and Industrialization: Historically, the Industrial Revolution acted as a primary catalyst. The localization of manufacturing near sources of power (such as water and coal) required a large, concentrated labor force. Factories offered paid work that attracted rural migrants, while the mechanization of agriculture reduced the need for labor on farms, pushing people toward urban centers.21
• Infrastructure and Surplus: Early urbanization was only possible due to improvements in agriculture and transportation. A surplus of food allowed rural areas to feed urban populations, while transport networks enabled the movement of these goods into cities.1
• Agglomeration Economies: Cities maximize internal economies of scale and external economies of agglomeration. By concentrating businesses and services, cities minimize costs related to transport and communication while providing a dynamic environment for trade, innovation, and specialized service activity.23
• Access to Services: People are drawn to cities by superior access to education, healthcare, and cultural amenities, which are more readily available in densely populated areas.3