Doctoral Publications
Cross-section data on the scientific productivity of PhD students in biochemistry.
data("PhDPublications")A data frame containing 915 observations on 6 variables.
Number of articles published during last 3 years of PhD.
factor indicating gender.
factor. Is the PhD student married?
Number of children less than 6 years old.
Prestige of the graduate program.
Number of articles published by student's mentor.
Online complements to Long (1997).
Long, J.S. (1990). Regression Models for Categorical and Limited Dependent Variables. Thousand Oaks: Sage Publications.
Long, J.S. (1997). The Origin of Sex Differences in Science. Social Forces, 68, 1297–1315.
## from Long (1997)
data("PhDPublications")
## Table 8.1, p. 227
summary(PhDPublications)
## Figure 8.2, p. 220
plot(0:10, dpois(0:10, mean(PhDPublications$articles)), type = "b", col = 2,
xlab = "Number of articles", ylab = "Probability")
lines(0:10, prop.table(table(PhDPublications$articles))[1:11], type = "b")
legend("topright", c("observed", "predicted"), col = 1:2, lty = rep(1, 2), bty = "n")
## Table 8.2, p. 228
fm_lrm <- lm(log(articles + 0.5) ~ ., data = PhDPublications)
summary(fm_lrm)
-2 * logLik(fm_lrm)
fm_prm <- glm(articles ~ ., data = PhDPublications, family = poisson)
library("MASS")
fm_nbrm <- glm.nb(articles ~ ., data = PhDPublications)
## Table 8.3, p. 246
library("pscl")
fm_zip <- zeroinfl(articles ~ . | ., data = PhDPublications)
fm_zinb <- zeroinfl(articles ~ . | ., data = PhDPublications, dist = "negbin")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.