population pyramid

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Related to Age Distribution: Population pyramid

pop·u·la·tion pyr·a·mid

graphic representation of the age and gender composition of a population, constructed by computing the percentage distribution of the population in each age and sex class.


all of the animals in a specifically defined area considered as a whole. The population may also be defined in modes other than geography, e.g. the cow population, a species specification, the nocturnal bird population.

binomial population
see binomial population.
population cartogram
a map of populations.
case population
see case population.
closed population
e.g. closed herd or flock; a population into which no introductions are permitted, including artificial insemination or embryo transfer; the population is genetically and/or hygienically isolated.
comparison population
see comparison population.
contiguous p's
the populations are separated but have a common border. Some diseases are very difficult to restrain from spreading from one population to the next.
control population
see control population.
population density
see population density.
experimental population
the population in which the experiment, or trial, is being conducted.
finite population
one capable of total examination by census.
genetic population
see deme.
genetically defined population
one in which the ancestry of the animals in it is known.
population genetics
deals with the frequency of occurrence of inherited characteristics in a population.
infinite population
cannot be examined as a total population because they may never actually exist but are capable of statistical importance.
population limitation
restricting the growth of an animal population by desexing, by culling or by managemental means of interfering with reproduction.
population mean
the mean of the population.
population numbers
see population size (below).
open population
one in which immigration in and out is unrestrained.
parent population
the original population about which it is hoped to make some inferences by examination of a sample of its constituent members.
population proportion
the percentage of the population that has the subject characteristics.
population pyramid
a graphic presentation of the composition of a population with the largest group forming the baseline, the smallest at the apex.
population at risk
see risk population (below).
risk population
the population which is composed of animals that are exposed to the pathogenic agent under discussion and are inherently susceptible to it. Called also population at risk. High or special risk groups are those which have had more than average exposure to the pathogenic agent.
population size
actual counting of a total population, the census method, is not often possible in large animal populations. Alternatives are by various sampling techniques including area trapping, the trapping of all animals in an area, the capture-release-recapture method, the nearest neighbor and line transect methods,
The population size is expressed as the population present at a particular instant. Alternatively it can be expressed as an animal-duration expression when the population is a shifting one and it is desired to express the population size over a period (e.g. cow-day).
stable population
a population which has constant mortality and fertility rates, and no migration, therefore a fixed age distribution and constant growth rate.
target population
in epidemiological terms the population from which an experimenter wishes to draw an unbiased sample and make inferences about it.
References in periodicals archive ?
Thus, the total age distribution component masked divergent influences of younger and older mothers on the overall preterm birth rate decline.
2] levels probably did not enter into past fertility decisions, and we assume that other determinants of emissions (such as current business cycles and the age distribution itself) did not enter past fertility decisions, either.
This paper has sought to render that source more useful by providing a methodology for estimating the age distribution of fathers whose details are not registered--those associated with so-called "paternity-not-acknowledged" ex-nuptial births.
But how does technology growth affect the age distribution of health spending?
For age distributions estimated from mixtures of length-at-age distributions, the EM (expectation-maximization) algorithm (Hasselblad, 1966; Hoenig and Heisey, 1987; Kimura and Chikuni, 1987), restricted least squares (Clark, 1981), and weak quasisolutions (Troynikov, 2004) have all been used.
It is of interest to compare the potential magnitude of the effect on output per capital of a changing workforce age distribution with that of increases in labour force participation rates (LFPRs).
One method for eliminating the confounding effect of a changing age distribution on changes in labor force participation is to focus, not on changes in the participation rate of the entire population, but on changes in the participation rate of specific age groups.
It is shown that not only would this require an immediate fall of fertility to below one child per woman, but that it would result in tremendous fluctuations in the age distribution over the coming century.
However, a shortcoming of this approach is that such "crude" rates can be influenced by the age distribution of the underlying population.
The economy could also be affected by changes in the age distribution, having a "major influence on the planning of government as well as the private sector in providing or selling goods and services to the population," say the researchers.
Surprisingly, China's age distribution is not that different from the advanced countries, especially with the sharp decline in number of births in the last 15 years (Figure 2).
Less obvious is the reason for interpreting the skewed age distribution of buyers as a problem.