translate.logit: Translates logit regression coefficients into percentages

In GDAtools: A Toolbox for Geometric Data Analysis and More

Description

Performs a logit regression and then computes the effects of covariates expressed in percentages (through two methods: 'pure' effects and 'experimental' effects; see Deauvieau, 2010)

Usage

translate.logit(formula,data,nit=0)

Arguments

formula	an object of class formula (or one that can be coerced to that class): a symbolic description of the model to be fitted. Every variables have to be factors.
data	a data frame containing the variables in the model
nit	number of bootstrap iterations for confidence interval computation. Default is 0, i.e. no confidence interval is computed.

Details

This function works with binomial as well as multinomial regression models. If the dependant variable has two factors, glm is used, if it has more than two factors multinom function (from nnet package) is used. The function expresses the regression coefficients as percentages through three distinct methods: raw percentages, 'pure effects' percentages and 'experimental effects' percentages (see Deauvieau, 2010). Bootstrap confidence interval are available only for binomial regressions.

Value

The function returns a list:

glm	An object of class glm or nnet (depending on the number of factors of the dependent variable)
summary	The results of summary function applied to reg element
percents	A matrix or a list of matrices (depending on the number of factors of the dependent variable) with regression coefficients expressed as percentages
boot.ci	A matrix or a list of matrices (depending on the number of factors of the dependent variable) with confidence intervals computed with bootstrap

Author(s)

Nicolas Robette

References

Deauvieau, J. (2010), 'Comment traduire sous forme de probabilites les resultats d'une modelisation logit ?', Bulletin of Sociological Methodology / Bulletin de Methodologie Sociologique 105(1), 5-23.

Deauvieau, J. (2011), 'Est-il possible et souhaitable traduire sous forme de probabilites un coefficient logit ? Reponse aux remarques formulees par Marion Selz a propos de mon article paru dans le BMS en 2010', Bulletin of Sociological Methodology / Bulletin de Methodologie Sociologique 112(1), 32-42.

Deauvieau, J. (2019), 'Comparer les resultats d’un modele logit dichotomique ou polytomique entre plusieurs groupes a partir des probabilites estimees', Bulletin of Sociological Methodology / Bulletin de Methodologie Sociologique 142(1), 7-31.

See Also

glm, multinom

Examples

  ## An example for binomial logit regression
  data(Music)
  translate.logit(Daily ~ Gender + Age, Music)
  
  ## An example for multinomial logit regression
  translate.logit(OnlyMus ~ Gender + Age, Music)

GDAtools documentation built on May 31, 2021, 5:08 p.m.