Data are taken from Loomis (2003). The study relates to a survey taken on reported frequency of visits to national parks during the year. The survey was taken at park sites, thus incurring possible effects of endogenous stratification.
loomis is saved as a data frame. Count models typically use anvisits as response variable. 0 counts are included
A data frame with 410 observations on the following 11 variables.
from Loomis (2003)
Hilbe, Joseph M (2007, 2011), Negative Binomial Regression, Cambridge University Press Loomis, J. B. (2003). Travel cost demand model based river recreation benefit estimates with on-site and household surveys: Comparative results and a correction procedure, Water Resources Research, 39(4): 1105
data(loomis) glmlmp <- glm(anvisits ~ gender + factor(income) + factor(travel), family=poisson, data=loomis) summary(glmlmp) exp(coef(glmlmp)) library(MASS) glmlmnb <- glm.nb(anvisits ~ gender + factor(income) + factor(travel), data=loomis) summary(glmlmnb) exp(coef(glmlmnb))