 There are three factors that affect the growth or decay of a certain region. 1. The birth rate 2. The death rate 3. The migration rate.

 Birthrate=(live births/Total population) x 1,000  Overview  The U.S. birth rate dipped in 2011 to the lowest ever recorded, led by a plunge in births to immigrant women since the onset of the Great Recession.  The overall U.S. birth rate, which is the annual number of births per 1,000 women in the prime childbearing ages of 15 to 44, declined 8% from 2007 to The birth rate for U.S.-born women decreased 6% during these years, but the birth rate for foreign-born women plunged 14%—more than it had declined over the entire period. The birth rate for Mexican immigrant women fell even more, by 23%.

 Population: The number of people living in a area  Demography: Is the area of sociology that engages in the study of human population  Birthrate: Is the term mostly use to refer to or describe the births of individuals among a population. To calculate the birthrate Demographers divide the number of live births in a particular year by the total population for that year.  Fertility: Refers to the actual number of birth occurring to women at childbearing age(14-44yrs)  Fecundity: The biological ability to conceive a child.

 Death rate = (Deaths/ Total population) x 1,000  Mortality: The number of deaths within a society  Infant Mortality rate: The annual number of deaths among infants under one per 1,000  Life expectancy :The average numbers an individual born in a particular year is expected to live

 Migration: the movement of people from specific location to another.  Migration Rate: the annual difference between in-migration and out-migration

 Growth rate : The rate at which a country ‘s population is increasing  Doubling time: The years necessary for a population to double in size

 In addition to studying the changes in population and size, Demographers also study the composition/ structure of the population. The factors that are taken into consideration are the distribution of sex and age when showing composition of the population.

 Two of the most discussed by demographers are  Malthusian Theory- This theory predicts that the population would soon reach astronomical numerals.  Demographic Transition Theory- This theory holds that population change is tied to a society’s level of technological development  Zero Population growth- at point at which the rate of birth and death produce almost a growth rate of zero.

 Are current population is of about 6.2 billion and it’s still growing although the rate of growth has dropped from 2% to 1.3% in the last 50 years.  Family Planning- the conscious decision by a couple to have and plan their number of children  Economic Improvements- The belief that some critics of planned parenthood have; they believe that in order to have a lower birth rate people most be more educated, healthier and a higher income.

 Preindustrial City- Cities first arose about 6,000years ago on the fertile banks.  The Industrial City- The nature of life in preindustrial cities changed little for almost 5,000 years. Then the industrial revolution produce an explosive growth in both the size and number of cities.  Over urbanization- A situation in which more people live in a city than it can actually be supported.

 -The Sociologists interest in urban life development and approach to the study of cities(1920’s-30’s)  Concentric Zone Model- A propose that came from Ernest W. Burgess that described urban structure. According to this model, a common city spread outward from the center forming a series of circles (zones)  Sector Model- Hoyt argued that growth occurs in wedge-shape sectors( not concentric circles)  Multiple Nuclei Model- Harris and Ullman suggested that a city does not develop around a single focal point, but a series.

 Urban Anomie Theory- According to this theory the city is an anonymous and unfriendly place, and to life there brings negative consequences  Compositional Theory- exams the way in which the composition of the city’s population is influenced Such as race nationality, education, ect…  Subcultural Theory- According to Claude S. Fischer, The characteristics of the city Encourages the formation of primary group relationships. Due to magnitude of the population of the cities it is possible for an individual to find another individual with similar believes and goals.