In sub-Saharan Africa, for example, a country's population will tend to have a higher proportion of children. Especially in sub-Saharan Africa and parts of Asia, urbanization rates are high and must be coupled with better efforts in urban expansion planning and slum upgrading. Based on the concept of the demographic dividend, however, this rising urbanization phenomenon could be called the urban dividend, urbanization as a window of opportunity to improve people's well-being when planning is properly undertaken.