lt.representativity {mortAAR}

Checks the representativity of the non-adult age groups in a mortAAR life table

Description

Weiss 1973, 46f. and Bocquet-Appel and Masset 1977 (see also Herrmann et al. 1990, 306f.) have devised indices which check if the non-adult age groups are represented in proportions as can be expected from modern comparable data. Whether this is really applicable to archaeological data-sets is a matter of debate.

Usage

lt.representativity(life_table)

Arguments

life_table

an object of class mortaar_life_table.

Details

Weiss chose the mortality (qx) as deciding factor and claimed that (1) the probability of death of the age group 10–15 (5q10) should be lower than that of the group 15–20 (5q15) and that (2) the latter in turn should be lower than that of age group 0–5 (5q0).
In contrast, Bocquet-Appel and Masset took the raw number of dead (Dx) and asserted that (1) the ratio of those having died between 5 and 10 (5D5) to those having died between 10 and 15 (5D15) should be equal or larger than 2 and that (2) the ratio of those having died between 5 and 15 (10D5) and all adults (>= 20) should be 0.1 or larger.
Due to the specific nature of the indices, they only give meaningful results if 5-year-age categories have been chosen for the non-adults.

Value

data.frame showing the indices and explaining their interpretation.

References

Herrmann B, Grupe G, Hummel S, Piepenbrink H, Schutkowski H (1990). Praehistorische Anthropologie: Leitfaden der Feld- und Labormethoden. Springer, Berlin.

Masset C, Bocquet J (1977). “Estimateurs en paléodémographie.” L’Homme, 17(4), 65–90.

Weiss KM, Wobst HM (1973). “Demographic Models for Anthropology.” Memoirs of the Society for American Archaeology, 27, i–186. ISSN 0081-1300.

Examples

schleswig <- life.table(schleswig_ma[c("a", "Dx")])
lt.representativity(schleswig)