Why does greater Kolkata contain more than half of West Bengal’s urban population?

Greater Kolkata serves as the dominant urban and economic center of eastern India, which explains why it concentrates such a significant portion of West Bengal’s urban population. This concentration is driven by several historical and geographical factors:1

• Economic Hub: As a major port and center for commerce, transport, and manufacturing, the city has long attracted migrants from across the region in search of employment. The area along the Hooghly River is heavily industrialized, providing a foundation for this dense urban development.123
• Historical Influxes: The city experienced massive population growth due to significant historical events, most notably the partition of Bengal in 1947 and the conflict in Bangladesh in the early 1970s, which triggered large-scale migrations of refugees into the city and its suburbs.45
• Regional Migration: Beyond refugees, Kolkata has consistently drawn a large number of migrants from neighboring states, such as Bihar, Odisha, and Uttar Pradesh, seeking work, further cementing its status as a primary destination for the state's urbanizing population.5