It was predicted by the United Nations Population Fund, that more than half of the world’s population will live in cities or urban areas. This happens mainly in developing countries of Africa and Asia.
UNPF predicted the unprecedented growth of population in urban areas of Africa and Asia by 2030. They say this will grow by 1.7 billion people which is more than the current population of US and China combined.
The problem with this growth of population in cities is that it results in increasing number of slums and radical nature in youth. For that reason the politicians have to make plans for balanced growth of economy and social things in the urban areas.