This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Projecting the growth of an age-structured population: approach to a stable age distribution Life table parameters [recall that p(x) = l(x+1)/l(x)] Definitions of stable population growth parameters x l(x) p(x) m(x) l(x)m(x) xl(x)m(x) v(x) 1.000 0.500 0.000 0.000 0.000 1.500 R(0) 1.500 1 0.500 0.800 1.000 0.500 0.500 3.000 T 1.8 Length of a generation (units are time intervals) 2 0.400 0.500 2.000 0.800 1.600 2.500 λ (approx) 1.253 3 0.200 0.000 1.000 0.200 0.600 1.000 1.500 2.700 This spreadsheet models a population with 4 cohorts (nobody survives to age class 4). It projects population growth assuming that survivorship (l(x)) and fecundity (m(x)) values are fixed constants. Births that happen during one interval only show up as newborns in the following interval. The default values for these parameters give a moderate rate of population growth. You can change the survivorship and fecundity values, and the starting age structure (these cells are green). Just overwrite these cells with new values, and the other calculations and graphs will change to reflect your modifications. Don't try to change non-...
View Full Document
- Spring '07
- Demography, Demographic economics, stable age distribution