Population Estimates

Question 1

Step Down Method

Answer 1

Apportionment based on data from larger area.

Question 2

American Community Survey

Answer 2

Rolling survey done every year, but not for the same group of people. Use average of data over five years for estimates.

Question 3

Fundamental drivers of pop change

Answer 3

1. Natural (births and deaths)
2. Net migration (inmigration minus outmigration)

Question 4

Trend Extrapolation

Answer 4

Pop projection method. Linear trend, exponential trend, Gompertz curve (s-shaped curve, has a carrying capacity)
Projecting what happened in the past out into the future.

Question 5

Allocation Methods

Answer 5

Pop projection method.

Ratio Method (step down) - smaller area proportional to a larger area.

Distributed Housing Unit Method: Pop(t) = Housing Units(t) x Occupancy Rate x Household Size. Can be used to calculate population between census years.

Question 6

Cohort Survival (Cohort Component)

Answer 6

Pop projection method.
Pop(t+1) = Pop(t) + Births(t to t+1) - Deaths(to to t+1) + Net Migration (to to t+1)
Births and deaths easier to track than migration

Fundamental population equation: The population in the next period is the current population + births - deaths + net-migration

Question 7

Social Explorer