Understanding migration and fertility issues would be very relevant in the context of changing demographic dimensions between developed and developing countries, in particular differing age structure of the populations between them. As the developing countries have opportunity for potential demographic dividend due to increase in the supply of labour force, the developed countries would be facing a shortage of labour force and health care burden for old age people. Further, this phenomenon will have repercussion with respect to movement of people from developing countries to developed countries and flow of economy at the global level. At the county level, interregional migrations seems to be increasing due to demographic diversity within the country. Rapid urbanization in the developing countries is another challenge due to rural-urban migration.