Search results
Results From The WOW.Com Content Network
In demography, demographic transition is a phenomenon and theory in the social sciences referring to the historical shift from high birth rates and high death rates to low birth rates and low death rates as societies attain more technology, education (especially of women), and economic development. [1]
Population momentum is a consequence of the demographic transition. Population momentum explains why a population will continue to grow even if the fertility rate declines or continues to decline even if the fertility rate grows. Population momentum occurs because it is not only the number of children per woman that determine population growth ...
A population history of the United States (Cambridge University Press, 2012) excerpt [permanent dead link ] Lahey, Joanna N. "Birthing a Nation: The Effect of Fertility Control Access on the Nineteenth-Century Demographic Transition," Journal of Economic History, 74 (June 2014), 482–508. Mintz Steven and Susan Kellogg.
Under federal law, the Immigration and Nationality Act of 1965, [39] the number of first-generation immigrants living in the United States has increased, [40] from 9.6 million in 1970 to about 38 million in 2007. [41] Around a million people legally immigrated to the United States per year in the 1990s, up from 250,000 per year in the 1950s. [42]
In the demographic transition model, the size and shape of population pyramids vary. In stage one of the demographic transition model, the pyramids have the most defined shape. They have the ideal big base and a skinny top. In stage two, the pyramid looks similar but starts to widen in the middle age groups.
A 2014 study published in the Proceedings of the National Academy of Sciences of the United States of America found that given the "inexorable demographic momentum of the global human population", even mass mortality events and draconian one-child policies implemented on a global scale would still likely result in a population of 5 to 10 ...
The Zelinsky Model of Migration Transition, [1] also known as the Migration Transition Model or Zelinsky's Migration Transition Model, claims that the type of migration that occurs within a country depends on its development level and its society type. It connects migration to the stages within the Demographic Transition Model (DTM).
In demography and population dynamics, the rate of natural increase (RNI), also known as natural population change, is defined as the birth rate minus the death rate of a particular population, over a particular time period. [1]