2.11 Forced and Voluntary Migration

Forced migration happens when people are made to move by violence, persecution, disaster or enslavement.

The Atlantic slave trade was the largest forced migration across an ocean in history. From the 1500s to the 1860s, about 12.5 million enslaved Africans were forced onto ships bound for the Americas, and about 10.7 million survived the voyage (SlaveVoyages database). Most were taken to Brazil and the Caribbean. The trade tore apart families and communities in West and Central Africa and shaped the population and culture of the Americas.

Today, the UN Refugee Agency (UNHCR) has counted more than 100 million forcibly displaced people worldwide every year since 2022.

The 1951 UN Refugee Convention defines a refugee as someone outside their country who has a well-founded fear of persecution because of race, religion, nationality, membership in a particular social group or political opinion. Wars and widespread violence also produce refugees.

An asylum seeker is officially recognized as a refugee only if their claim is accepted. Internally displaced persons often outnumber refugees, because crossing a border can be dangerous, expensive or impossible. The war that began in Sudan in 2023 created one of the world's largest displacement crises, with millions of people displaced inside Sudan as well as across its borders.

• Internal migration: moving within one country. Between about 1910 and 1970, roughly 6 million African Americans left the rural South for cities in the North and West in the Great Migration, driven by work opportunities and escape from segregation and racial violence.
• Rural-to-urban migration: moving from the countryside to cities, the largest flow in the world today. China's rural-to-urban migration involves hundreds of millions of people.
• Step migration: moving in a series of smaller stages, such as village to town to big city.
• Chain migration: following relatives or neighbors who moved earlier, often to the same city or even the same neighborhood.
• Guest workers: people who move for temporary jobs and are expected to return home. West Germany recruited guest workers, many from Turkey, from 1955 to 1973; Gulf states rely heavily on temporary foreign workers.
• Transhumance: moving herds seasonally between pastures, such as herders in the Alps taking cattle to high meadows in summer, or Fulani herders in West Africa following the rains.
• Transnational migration: migrants who live in one country while keeping strong ties to another, sending remittances, visiting often and staying involved in home-country life.

Some moves are hard to classify. A family leaving a region after years of failed harvests or extreme poverty technically chose to move, but they may have had few real options. Geographers increasingly talk about a spectrum from forced to voluntary instead of two neat boxes.