Constant Global Population with Demographic Heterogeneity

By Cohen, Joel E. | Demographic Research, January-June 2008 | Go to article overview

Constant Global Population with Demographic Heterogeneity


Cohen, Joel E., Demographic Research


Abstract

To understand better a possible future constant global population that is demographically heterogeneous, this paper analyzes several models. Classical theory of stationary populations generally fails to apply. However, if constant global population size P(global) is the sum of all country population sizes, and if constant global annual number of births B(global) is the sum of the annual number of births of all countries, and if constant global life expectancy at birth e(global) is the population-weighted mean of the life expectancy at birth of all countries, then B(global) * e(global) always exceeds P(global) unless all countries have the same life expectancy at birth, in which case B(global) * e(global) = P(global).

(ProQuest: ... denotes formulae omitted.)

1. Introduction

In most countries of the world, human birth rates have been dropping and human life expectancies have been increasing (apart from countries severely afflicted by HIV-AIDS, economic disruption, and violent disorder). The end of global population growth lies within the range of plausible scenarios for the coming half-century or century (United Nations Population Division 2005). For example, in its low variant prepared in 2004, the UN Population Division projected that global population would peak in 2040 and then decline (until 2050, the horizon of the projection). In its medium variant, the projected global net rate of reproduction fell to 1.00 by 2025-2030 and thereafter continued to decline, implying a future cessation of global population growth. Yet no demographic projections assume that all countries will have identical demographic characteristics.

It is therefore timely and useful to model a global population with unchanging total size and demographic variation among countries. This paper presents models of constant global populations and an apparently new inequality that connects population size, birth rates and life expectancy in a heterogeneous stationary population.

These models differ from graded models of stationary populations (e.g., Seal 1945; Vajda 1947; Bartholomew 1963; Keyfitz 1973), which assume that individuals advance through a linear succession of grades. Graded models have been used to study promotion in hierarchical organizations.

Coale (1972) emphasized that any earthbound population must have an average rate of growth that approaches zero as the time interval over which it is observed increases without limit, because infinite increase (implied by an average rate of increase that is positive, no matter how small) is impossible on a finite Earth. Numerous models have been proposed to investigate how populations approach stationary size, including models with and without age structure, with and without migration among subpopulations, and with rates of birth, death and migration that are constant or changing in time (Espenshade 1978; Feeney 1971; Kim and Schoen 1996; Land and Rogers 1982; Le Bras 1971; Rogers 1968, 1990, 1995; Rogers and Castro 1981; Rogers and Henning 1999; Rogers et al. 2004; Romaniuc 2005; Schoen 1988, 2002; Schoen and Kim 1993, 1998-not an exhaustive list). These thoughtful and useful studies do not appear to have attained the results presented here.

2. The classical stationary population model

The classical stationary population model describes an age-structured, single-sex population, closed to migration, with a constant number of births B per year equal to the constant number of deaths D per year so that the total population size P remains constant. The life table or survival function is the probability that a newborn individual survives to any given age or older, and is the complement of (i.e., one minus) the cumulative distribution function of length of life. The life table l(x) depends on age only; it is assumed constant over time and applicable to all individuals. These attributes define a homogeneous stationary population.

A homogeneous stationary population arises in stable population theory from six conditions (Ryder 1975, p. …

The rest of this article is only available to active members of Questia

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Note: primary sources have slightly different requirements for citation. Please see these guidelines for more information.

Cited article

Constant Global Population with Demographic Heterogeneity
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen
Items saved from this article
  • Highlights & Notes
  • Citations
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Search by... Author
    Show... All Results Primary Sources Peer-reviewed

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.