-+Human+Population+Growth

toc == Dem ﻿ ography ==
 * Demography is the the study of populations and how they vary in numbers.
 * The study of Demography is very geneneral and can be applied to any kind of dynamic population that changes over time and or space.
 * There are two different ways to collect data for human demography;
 *  Direct Data: wich comes from vital statistics that track all birth and deaths in the worls as well as certain changes in legal status (marraige, divorce.. etc.)
 *  Census: a national goverment conducted attempts to count every person in every country. This may not be as exact as direct data due to the fact that it is only collected about once every ten years.

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= Demographic Transition =
 * Demographic transition is used to represent the transition from high birthday and death rates to low birth and death rates.
 * This generally happens in five stages;
 * STAGE ONE: In a pre-industrial society the death and birth rates fluctuate rapidly due simply to natural disasters.
 * STAGE TWO: This is where the death rate starts in decrease and the population increases. There is usually something like an improvement in the food supply or an improvement in health.
 * STAGE THREE: This is when the population starts to mellow out and the birth rate isn't so rapid. There are many factors that contribute to this but most are speculative.
 * STAGE FOUR: This is the the best point in a population. This is when the birth and death rates are both mellow and fluctuating and the population is high and stable.
 * STAGES FIVE?: The original Demographic Transition model started with just for stages, but some theories think that with the changing times a fifth stage is needed to represent countries that now have sub-replacment fertility, meaning there have two or less kids per set of parents.