Rural flight (also known as rural-to-urban migration or rural exodus) is the migratory pattern of peoples from rural areas into urban areas. It is urbanization seen from the rural perspective. In industrializing economies like Britain in the eighteenth century or East Asia in the twentieth century, it can occur following the industrialization of primary industries such as agriculture, mining, fishing, and forestry—when fewer people are needed to bring the same amount of output to market—and related secondary industries (refining and processing) are consolidated. Rural exodus can also follow an ecological or human-caused catastrophe such as a famine or resource depletion. These are examples of push factors. The same phenomenon can also be brought about simply because of higher wages and educational access available in urban areas; examples of pull factors. Once rural populations fall below a critical mass, the population is too small to support certain businesses, which then also leave or close, in a vicious circle. Even in non-market sectors of the economy, it becomes proportionately more expensive for governments to provide services to smaller and more dispersed populations, which can lead to closures of state-funded offices and services, which further harm the rural economy. Schools are the archetypal example because they influence the decisions of parents of young children: a village or region without a school will typically lose families to larger towns that have one. But the concept (urban hierarchy) can be applied more generally to many services and is explained by central place theory. Government policies to combat rural flight include campaigns to expand services to the countryside, such as electrification or distance education. Governments can also use restrictions like internal passports to make rural flight illegal. Economic conditions that can counter rural depopulation include commodities booms, the expansion of outdoor-focused tourism, and a shift to remote work, or exurbanization. To some extent, governments generally seek only to manage rural flight and channel it into certain cities, rather than stop it outright as this would imply taking on the expensive task of building airports, railways, hospitals, and universities in places with few users to support them, while neglecting growing urban and suburban areas. Historical trends Prior to the Industrial Revolution, rural flight occurred in mostly localized regions. Pre-industrial societies did not experience large rural-urban migration flows primarily due to the inability of cities to support large populations. Lack of large employment industries, high urban mortality, and