Stationarity Zero Growth Checker
Classify zero population growth from an annual growth rate or a two-census count pair, treating |r| within the stated tolerance as stationary, above it as growing and below negative it as shrinking.
Description
Classify zero population growth from an annual growth rate or a two-census count pair, treating |r| within the stated tolerance as stationary, above it as growing and below negative it as shrinking.
Classify zero population growth from an annual growth rate or a two-census count pair, treating |r| within the stated tolerance as stationary, above it as growing and below negative it as shrinking.1
When to use Stationarity Zero Growth Checker
Use this stable-population relationship for analytical schedules whose fertility, mortality, migration assumptions, and age intervals match the model.
- Source
- Supply an explicit rate, or derive ln(P2/P1)/t from census counts.
- Growth rate r
- Annual growth rate r when the source is 'rate'.
- P1
- Population at the first census P1 (counts source).
- P2
- Population at the second census P2 (counts source).
- Years
- Years between the censuses t (counts source).
- Tolerance
- Absolute |r| band treated as zero growth.
How the method works
- r
- Annual growth rate used for the classification.
- Status
- Zero-growth classification within tolerance.
Limitations and assumptions
Stable-population identities assume fixed vital rates and usually a closed population. Real populations with changing schedules or migration may be far from the implied equilibrium.
Alternative or Complementary measures
Compare the stable-population result with an observed age distribution or a cohort-component model using changing schedules. The difference indicates how strongly the equilibrium assumption shapes the result.
References
-
Euler–Lotka equation — Wikipedia contributors
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