| Impacts {CoDaImpact} | R Documentation |
Computation of elasticities in CoDa regression models
Description
This function computes elasticities and semi-elasticities for CoDa regression model. where we have to distinguish four cases:
Y and X are both compositional: this leads to an elasticity
Y is compositional and X is scalar: this leads to a semi-elasticity
Y is scalar and X is compositional: this leads to a semi-elasticity
Y and X are both scalar: this case is not implemented as it leads to constant marginal effects
Usage
Impacts(object, Xvar = NULL, obs = 1)
Arguments
object |
an object of class "lmCoDa" |
Xvar |
a character indicating the name of one explanatory variable |
obs |
a numeric that refers to the indicator of one observation |
Details
The mathematical foundation for elasticity computations in CoDa model come from Morais and Thomas-Agnan (2021). Dargel and Thomas-Agnan (2024) present further results and illustrations.
Value
a matrix
Author(s)
Lukas Dargel
Rodrigue Nasr
References
Dargel, Lukas and Christine Thomas-Agnan, “Pairwise share ratio interpretations of compositional regression models”, Computational Statistics & Data Analysis 195 (2024), p. 107945
Morais, Joanna and Christine Thomas-Agnan. "Impact of covariates in compositional models and simplicial derivatives." Austrian Journal of Statistics 50.2 (2021): 1-15.
Examples
res <- lmCoDa(YIELD ~ PRECIPITATION + ilr(TEMPERATURES), data = head(rice_yields,20))
Impacts(res, Xvar = "TEMPERATURES")