Predicted Values and Discrete Changes for GLM

Functions to calculate predicted values and the difference between the two cases with confidence interval for lm() [linear model], glm() [general linear model], glm.nb() [negative binomial model], polr() [ordinal logistic model], multinom() [multinomial model] and tobit() [tobit model] using Monte Carlo simulations or bootstrap. Reference: Bennet A. Zelner (2009) .