Urbanization is almost always caused by the high concentration of jobs for skilled workers and professionals in urban centers and the relative lack of employment opportunities in rural areas. Additionally, as developing countries move away from economies based primarily on agriculture, many farmers and their children are becoming industrial workers instead. Most heavy industry is usually located around major cities and this forces people to move away from rural areas.
As this continues, these poorer countries should grow over time and become wealthier nations in theory.
Jill
Jill