pop.predict: Probabilistic Population Projection

Description

The function generates trajectories of probabilistic population projection for all countries for which input data is available, or any subset of them.

Usage

pop.predict(end.year = 2100, start.year = 1950, present.year = 2010, 
    wpp.year = 2010, countries = NULL, 
    output.dir = file.path(getwd(), "bayesPop.output"),
    inputs = list(popM=NULL, popF=NULL, mxM=NULL, mxF=NULL, srb=NULL,
        pasfr=NULL, mig.type=NULL, migM=NULL, migF=NULL,
        e0F.file=NULL, e0M.file=NULL, tfr.file=NULL,
        e0F.sim.dir=NULL, e0M.sim.dir=NULL, tfr.sim.dir=NULL), 
    nr.traj = 1000, replace.output = FALSE, verbose = TRUE)

Arguments

end.year

End year of the projection.

start.year

First year of the historical data.

present.year

Year for which initial population data is to be used.

wpp.year

Year for which WPP data is available.

countries

Array of country codes or country names for which a projection is generated. If it is NULL, all available countries are used. If it is NA and there is an existing projection in output.dir and replace.output=FAL

output.dir

Output directory of the projection. If there is an existing projection in output.dir and replace.output=TRUE, everything in the directory will be deleted.

inputs

A list of file names where input data is stored. It contains the following elements (names of default datasets which are used if the corresponding element is NULL are shown in brackets): [object Object],[object Object],[object Object],[ob

nr.traj

Number of trajectories to be generated. If any of the simulations in e0M.file/e0M.sim.dir, e0F.file/e0F.sim.dir and tfr.file/tfr.sim.dir contains less trajectories than nr.traj, the number is set to the

replace.output

Logical. If TRUE, everything in the directory output.dir is deleted prior to the prediction.

verbose

Logical controlling the amount of output messages.

Value

Object of class bayesPop.prediction with the following elements:
output.directoryFull path to the projections.
nr.trajThe actual number of trajectories of the projections.
quantilesThree-dimensional array of projection quantiles (countries x number of quantiles x projection periods). The second dimension corresponds to the following quantiles: $0,0.025,0.05,0.1,0.2,0.25,0.3,0.4,0.5,0.6,0.7,0.75,0.8,0.9,0.95,0.975,1$.
traj.mean.sdThree-dimensional array of projection mean and standard deviation (countries x 2 x projection periods). First and second matrix of the second dimension, respectively, is the mean and standard deviation, respectively.
quantilesM, quantilesFQuantiles of male and female projection, respectively. Same structure as quantiles.
traj.mean.sdM, traj.mean.sdFSame as traj.mean.sd corresponding to male and female projection, respectively.
quantilesMage, quantilesFageFour-dimensional array of age-specific quantiles of male and female projection, respectively (countries x age groups x number of quantiles x projection periods). The same quantiles are used as in quantiles.
quantilesPropMage, quantilesPropFageArray of age-specific quantiles of male and female projection, respectively, divided by the total population. The dimensions are the same as in quantilesMage.
estim.yearsVector of time for which historical data was used in the projections.
proj.yearsVector of projection time periods starting with the present period.
inputsList of input data used for the projection.
countriesMatrix of countries for which projection exists. It contains two columns: code, name.
agesVector of age groups.

Details

The population projection is computed using the Cohort Component method and is based on an algorithm used by the United Nation Population Division. For each country, one projection is calculated for each trajectory of male and female life expectancy and TFR. This results in a set of trajectories of population projection which forms its posterior distribution. The trajectories of life expectancy and TFR can be given either in its binary form generated by the packages bayesLife and bayesTFR, respectively (as directories e0M.sim.dir, e0F.sim.dir, tfr.sim.dir of the inputs argument), or they can be given as ASCII tables in csv format, see above.

The projection is generated sequentially country by country. Results are stored in a sub-directory of output.dir called prediction. There is one binary file per country, called totpop_country$x$.rda, where $x$ is the country code. It contains six objects: totp, totpf, totpm (trajectories of total population, female and male, respectively), totp.hch, totpf.hch, totpm.hch (the UN half-child variant for total population, female and male, respectively). Furthermore, an object of class bayesPop.prediction is stored in the same directory in a file prediction.rda. It is updated every time a country projection is finished.

To access a previously stored prediction object, use get.pop.prediction.

Examples

Run this code

sim.dir <- tempfile()
# Countries can be given as a combination of numerical codes and names
pred <- pop.predict(countries=c("Netherlands", 218, "Madagascar"), nr.traj=10, 
           output.dir=sim.dir)
pop.trajectories.plot(pred, "Ecuador", sum.over.ages=TRUE)
unlink(sim.dir)

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