mortAAR (version 1.1.6)

lt.correction: Calculates a corrected life table from a mortAAR life table

Description

It is generally assumed that most skeletal populations lack the youngest age group. Life tables resulting from such populations will necessarily be misleading as they lead to believe that the mortality of younger children was lower than it actually was and that life expectancy was higher. For correcting these missing individuals, Bocquet-Appel and Masset (1977; see also Herrmann et al. 1990, 307) conceived of several calculations based on regression analyses of modern comparable mortality data. However, the applicability of these indices to archaeological data is highly debated and does not necessarily lead to reliable results. Therefore, the correction needs to be weighted carefully and ideally only after the representativity of the base data has been checked with function lt.representativity.

Usage

lt.correction(life_table, agecor = TRUE, agecorfac = c(), option_spline = NULL)

Value

a list containing a data.frame with indices e0, 1q0 and 5q0 as well as mortality rate m and growth rate r according to Bocquet-Appel and Masset showing the computed exact value as well as ranges and an object of class mortaar_life_table with the corrected values.

• e0: Corrected life expectancy.

• 1q0: Mortality of age group 0--1.

• 5q0: Mortality of age group 0--5.

Arguments

life_table

an object of class mortaar_life_table.

agecor

logical, optional. Passed to life.table.

agecorfac

numeric vector, optional. Passed to life.table.

option_spline

integer, optional. Passed to life.table.

Details

For the parameters see the documentation of life.table.

References

masset_bocquet_1977mortAAR

herrmann_prahistorische_1990mortAAR

Examples

# Calculate a corrected life table from real life dataset.
schleswig <- life.table(schleswig_ma[c("a", "Dx")])
lt.correction(schleswig)