Rural-urban migration is increasing urbanization globally. People migrate from rural to urban areas due to push factors in rural areas like lack of jobs, poverty, and poor infrastructure as well as pull factors of the city like more jobs and economic opportunities, improved standards of living, and access to services. Urbanization grew rapidly in now-developed countries during industrialization as people moved to cities for factory and mine jobs. In poorer countries today, high fertility rates and natural increase in cities also contribute to urban growth, as do cities being centers of industry and opportunity.