Using examples, explain the reasons why rural-urban migration occurs.

Rural-urban migration - the movement of indivdiuals from rural to urban areas - is the product of a plethora of push and pull factors, as exhibited by Lee's push-pull theory. Migration from rural to urban Brazil, for example, occurs as a result of a variety of push factors, including low-paid menial labour (often agricultural) that has become increasingly mechanized, as well as poor quality standards of living for rural workers, such as land, lack of services (schools, hospitals, electricity, water supply) as well as poor quality housing. Pull factors in urban Brazil include the prospect of industrial labour (such as in factories), greater governmental provision of schools and health services, as well as potential for workers to access the urban formal economy (in comparison to informal labour in rural areas). Better entertainment, a wider supply of housing, are also pull factors, which, for many rural-urban migrants, becomes an important factor in the migration process, such that future generations (and children) can benefit. Nevertheless, it must be recognized that, in reality, the process of rural-urban migration is often much more complicated and uneasy for migrants: the pull factors attracting migrants to urban Brazil are often unrealized, and many migrants often reside in informal settlements (such as favelas in Rio) and work in low-paid, often dangerous, informal labour.