linguistic:paraphrasing
Economic motives

Some migrants choose to leave rural communities to pursue economic opportunity in urban areas. Greater economic opportunities can be real or perceived. According to the Harris-Todaro Model, migration to urban areas will continue as long as "expected urban real income at the margin exceeds real agricultural product" (127). However, sociologist Josef Gugler points out that while individual benefits of increased wages may outweigh the costs of migration, if enough individuals follow this rationale, it can produce harmful effects such as overcrowding and unemployment on a national level. This phenomenon, when the rate of urbanization outpaces the rate of economic growth, is known as overurbanization. With the rise of industrial agriculture, mechanization has reduced the number of jobs in rural communities.