Urbanization and Historic Migration Waves

Urbanization, the shift of a population from predominantly rural to predominantly urban residence, is one of the defining demographic processes of the last two centuries. In 1950, according to the UN's World Urbanization Prospects, only about 30 percent of the world's population lived in urban areas; by 2023 that share had risen past 57 percent, and the UN projects roughly 68 percent of humanity will be urban by 2050. The process has unfolded unevenly: Latin America and Northern America urbanized earliest and most completely, with over 80 percent of their populations already urban, while Africa and parts of South Asia remain the least urbanized major regions, near 45 percent and 35 percent respectively, but are now urbanizing faster than any other region in history. Unlike Europe's nineteenth-century urbanization, closely tied to industrial factory employment, much of today's fastest urban growth in Sub-Saharan Africa and South Asia is driven as much by natural population increase within cities and displacement from rural poverty or conflict as by formal industrial job creation, which helps explain the large share of urban residents in cities such as Lagos or Dhaka who live in informal settlements rather than formal housing.