Census and Age Structure Flashcards
Population (empirical population defintion)
collection of people alive at a specified point in time who meet certain criteria
Population (conceptual population definition)
collectivity of people that persists over time even though its members are always changing
Important characteristics of populations
size, composition, distribution, dynamics (changes over time)
Growth balance equation
PopulationT2 = populationT1 + B - D + I - O
What do I and O stand for in the population migration equation
In migration and out migration
Natural increase/decrease
B - D (babies born - deaths)
Net migration
I - O
Demographic rates
a fraction to measure events (only applicable to the empirical definition of population)
How to set up a demographic rate
Numerator: What event are we measuring and over what time period
Denominator: Who is at risk of experiencing an event
Person years of exposure
the population’s amount of exposure to the risk of the event
Rate of population growth
(P2 - P1)/P1
Crude birth rate
births/P1
Crude death rate
deaths/P1
Rate of net migration
(I-O)/P1
Goal of the census
gain a full count of the alive population on a specific date
What are the impacts of the census
allocation of representatives, allocation of federal funding
Problems with data collection for the census
bias (statistical errors, not beliefs), response rates, only head of households fill out the form, undercounted populations
Vital registration system
formal, bureaucratic system for recording births and deaths
Excess mortality
compare expected to observed number of deaths (regardless of causes)
P score of mortality
the difference between expected and actual percentages of deaths
Error of closure
X, people who were missed during the counting leading to errors in data
Population age structure
the number of people in the population at a certain age
Population pyramids
Breaks the population down by age and sex, a visual
Abridged population pyramid
combines age into 5 year increments, most common
