demographic data & pop over time Flashcards
2 types of data
primary
secondary
what is primary data
- Data collected by you specifically for the purpose in mind
- Generally fresh and collected for the first time
- Collected under your control
e.g. You’re interested in the views of FSU students regarding population policies - You design a questionnaire to collect this information
examples of quantitive and qualitative primary data
- quantitive = experiments, surveys
- qualitative = focus groups, human observation, case studies
advantages of primary data
- Applicable and usable
- Accurate and reliable
- Up-to-date
- Greater control
- Addresses specific research interest
disadvantages of primary data
- Expensive
- Not immediately available
- Time consuming
what is secondary data
- Data collected by someone else
- Collected for a different purpose
- Sometimes called “exhaust data.”
- The data are being reused, usually in a different context
- e.g. You use your friend’s questionnaire of FSU students regarding population policies to investigate something different
advantages of secondary data
- Inexpensive
- Easily accessible
- Immediately available (time saving)
- Relevant
- Complements primary data
examples of secondary data external sources and administrative records
- external sources = Census, Surveys, Social Media
- administrative records = birth records, Post Office
addresses, Population Registers
disadvantages of secondary data
- May be inaccurate
- May be inconsistent
- May be inaccessible
- May be outdated
- Variations in definitions of terms
- Different units of measurement
- Inconvenient to compare
3 sources of demographic data
- Registration of vital statistics
◦ population processes of births and deaths - Census of population
◦ population, demographic structure and
characteristics - Administrative data
◦ Local population changes, geographic mobility
and migration
what is the Registration of Vital Statistics
- Primarily administrative
- Collects data on vital events (live births,
deaths, marriages, divorces, etc.) - e.g. bills of mortality - used as reminder to produce life expectancy
Registration of Vital Statistics advantages
- Continuously collected
- May provide both numerator and denominator (Infant Mortality Rate)
- Small area data are available
- Base for testing the accuracy of censuses and surveys
Registration of Vital Statistics disadvantages
- Uncertain coverage.
- Limited background information
- Time reference inconsistent with denominator
- May come from third party
- Easily disrupted by political/economic events
what is Census of population
- The term “census” = Latin word of assess
- Ancient censuses differed from modern censuses - they were largely used for taxation + military purposes
- the largest peacetime activity undertaken by the
federal government - it’s our civic responsibility to complete the Census - populations in the census = de facto population + de jure population - based on usual residence (where they sleep (U.S.,Canada, Mexico))
what is the de facto population in the census
people who are in a given territory on census day - can think of it as daytime population
what is the de jure population in the census
people who legally “belong” to a given area, regardless of whether they were there on the day of the census - can think of it as nighttime population
whats the purpose of the census
To conduct a census of population and housing and disseminate the results to the President, the States, and the American People
primary uses:
- Apportion representation among states
- Draw congressional and state legislative districts, school districts, and voting precincts
- Distribute federal dollars to states <- $400 billion per year
- Provide detailed information on the populace
- Population Benchmark for other surveys
overview of how a census is designed / how it works
- establish where people are - where are all the housing units? - satellite imagary, postal etc
- motivate people to respond
- count the population
- release census results - has to be delivered to president at end of census year
**counting housing units to then count the actual number of people
- LUCA allows people to update their addresses
what is the census day (count date)
April 1 (XXX0)= census day - always use base number for population
July 1 = midway point - use to look at population change over time
what is the long form and short form of census
- LF = 40 pages - contains all the good stuff e.g. how many toilets are in your house - this one was eventually eliminated - ACS is a replacement to this
- SF = 6 pages - essentially 10 questions about basic stuff e.g. age, sex
advantage of ACS
on-going collection so new questions can be added
- In 2015 the CB released its first internet question
data - was not a concern in 2005 - would not know important data about internet in households without the ACS
2 primary data products published by ACS
1-year + 5-year estimates
- Areas with more than 65k people, have both 1-
year and 5-year estimates
- smaller areas have to wait longer for immediate intelligence
- CB used to publish 3-year estimates, but those are discontinued
what are the ACS data products
- Census Bureau suggests comparisons between
estimates should not include overlapping years - BUT, some companies are treating the 5-
year estimates as 1-year estimates based on the
mid-points <- Not a CB recommendation
2 errors you can get in CB
- margins of error
- Net Coverage Error
