The factors in migration include high rent, industrialization, gentrification of the inner quarters, transformation of the living space in offices and the improved affluence among the working families. Loss of population is city was one of most serve among the international municipalities and largest for any had achieved over 2,000,000 residents.

Paris is among most densely populated areas in world, density of city, excluding outlying woodland parks and Vincennes was about 24,448 inhabitants at par kilometer square in year 1999 of official census.

It could be easily compared with some Asian megapolis, and even it including two woodland areas and its population density was about 20,164 inhabitants at per kilometer square, which was 5 th most densely populated in France. Sparsely populated quarters are western and the central office with administration focused on arrondissements.

Paris city covers area that is much smaller than urban area, at present real urbanization of Paris is defined by Pole Urbain statistical area, it covers about 2,723 kilometers square of are that is about 26 times larger than city itself.

Administration of the Paris's urban growth can be divided between its surrounds and itself, closest ring of Paris has three adjoining departments that are carefully saturated with the urban rate of growth, ring of departments outside grande couronne, are covered in inner region by urbanization of city. Agglomeration of city has shown steady growth rate sine end of late 16 th century of France Wars, save brief setbacks during French Revolution and the 2 nd World War.