Premium
Obtaining Birth and Mortality Patterns From Structured Population Trajectories
Author(s) -
Wood S. N.
Publication year - 1994
Publication title -
ecological monographs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.254
H-Index - 156
eISSN - 1557-7015
pISSN - 0012-9615
DOI - 10.2307/2937054
Subject(s) - smoothness , population , birth–death process , statistics , mathematics , population model , demography , birth rate , mortality rate , spline (mechanical) , stage (stratigraphy) , confidence interval , age structure , population size , econometrics , biology , research methodology , mathematical analysis , paleontology , structural engineering , sociology , engineering
A method is presented for unravelling the demographic equation for structured populations. A solution to the McKendrick—von Foerster equation is constructed using spline functions and this is fluted to stage—structure population data in such a way that the solution is smooth, positive, and does not imply negative death rates. The smoothness of the surface, and hence the complexity of the population model, is determined in a statistically optimum manner using cross validation. Time— and age—dependent death rates can be obtained as well as time—dependent birth rates. Confidence intervals are obtained for population size and death rates that give a 95% probability that the true population dynamics are within the intervals. Practical application of the method is demonstrated, and comparison made with three alternative methods. The method requires estimates of stage populations at a series of times and estimates of the durations of those stages, or age ranges covered by the stages. The stage durations may vary with time.