The long-term objectives of this project are to develop and extend methods for the projection and dynamic analysis of human populations.
The specific aims of the proposed work involve three main areas of inquiry. First, the dynamics of a parity-progression model of birth projection will be analyzed. This continuous-time model is built upon distributions of the time of birth for women who are classified by parity, i.e., by the number of children already born. A demographic sensitivity analysis of this model will be done to examine changes in growth rate, transient properties, and age-composition given arbitrary changes in mean and variance of timing of first and later children, and changes in parity progression ratios. Second, several essential aspects of stochastic demographic models will be analyzed. The theory of stochastic reproductive value will be developed and the mean and variances in the stochastic model used to characterize the effects of stochasticity on future generations. A demographic sensitivity analysis will be performed on growth rate and age distribution of stochastic models given arbitrary changes in birth and death schedules. Finally some exactly soluble and approximately soluble analytical models will be explored to develop further insight into the properties of stochastic models. Third, the robustness of an internally driven dynamic analysis of the Easterlin effect will be examined. The main question to be considered is the robustness of cyclical dynamics given a blurring of the precise age composition of a cohort. The proposed work will treat the effective birth cohort affecting population fertility as a sum over actual births in a finite time interval around the time of birth.
The aim i s to see how the resulting averaging will affect intrinsic cycles.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD016640-04
Application #
3313808
Study Section
Social Sciences and Population Study Section (SSP)
Project Start
1982-08-01
Project End
1986-07-31
Budget Start
1985-08-01
Budget End
1986-07-31
Support Year
4
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Portland State University
Department
Type
Schools of Arts and Sciences
DUNS #
City
Portland
State
OR
Country
United States
Zip Code
97207
Tuljapurkar, S; Li, N; Feldman, M W (1995) High sex ratios in China's future. Science 267:874-6
Wiener, P; Tuljapurkar, S (1994) Migration in variable environments: exploring life-history evolution using structured population models. J Theor Biol 166:75-90
Tuljapurkar, S (1993) Entropy and convergence in dynamics and demography. J Math Biol 31:253-71
Tuljapurkar, S; John, A M (1991) Disease in changing populations: growth and disequilibrium. Theor Popul Biol 40:322-53
Tuljapurkar, S (1990) Age structure, environmental fluctuations, and hermaphroditic sex allocation. Heredity 64 ( Pt 1):1-7
Tuljapurkar, S (1990) Delayed reproduction and fitness in variable environments. Proc Natl Acad Sci U S A 87:1139-43
Tuljapurkar, S (1989) An uncertain life: demography in random environments. Theor Popul Biol 35:227-94
Tuljapurkar, S (1987) Cycles in nonlinear age-structured models. I. Renewal equations. Theor Popul Biol 32:26-41
Tuljapurkar, S (1985) Population dynamics in variable environments. VI. Cyclical environments. Theor Popul Biol 28:1-17