lileecarter.estimate {MortCast}

Coherent Lee-Carter Estimation

Description

Estimate coherent Lee-Carter parameters (Li and Lee 2005).

Usage

lileecarter.estimate(mxM, mxF, nx = 5, ...)

Arguments

mxM

A matrix of male age-specific mortality rates where rows correspond to age groups and columns correspond to time periods. For 5-year age groups, the first and second rows corresponds to 0-1 and 1-5 age groups, respectively. Rownames define the starting ages of the respective groups.

mxF

A matrix of female mortality rates of the same shape as mxM.

nx

Size of age groups. Should be either 5 or 1.

...

Additional arguments passed to leecarter.estimate.

Details

The coherent Lee-Carter parameters for male and female mortality rates share the same b_x which is the average of the age-specific b_x parameters.

The function in addition computes the ultimate b^u_x as defined in Li et al. (2013) based on the coherent b_x.

Value

List containing elements bx (coherent b_x parameter), ultimate.bx (ultimate b^u_x parameter), ages (age groups), nx (age group interval), and lists female and male, each with the Lee-Carter parameters.

References

Li, N. and Lee, R. D. (2005). Coherent mortality forecasts for a group of populations: An extension of the Lee-Carter method. Demography, 42, 575-594.

Li, N., Lee, R. D. and Gerland, P. (2013). Extending the Lee-Carter method to model the rotation of age patterns of mortality decline for long-term projections. Demography, 50, 2037-2051.

Examples

data(mxM, mxF, package = "wpp2017")
country <- "Germany"
mxm <- subset(mxM, name == country)[,4:16]
mxf <- subset(mxF, name == country)[,4:16]
rownames(mxm) <- rownames(mxf) <- c(0,1, seq(5, 100, by=5))
lc <- lileecarter.estimate(mxm, mxf)
plot(lc$bx, type="l")
lines(lc$ultimate.bx, lty=2)