PhDPublications {AER} | R Documentation

## Doctoral Publications

### Description

Cross-section data on the scientific productivity of PhD students in biochemistry.

### Usage

    data("PhDPublications")

### Format

A data frame containing 915 observations on 6 variables.

articles

  Number of articles published during last 3 years of PhD.

gender

  factor indicating gender.

married

  factor. Is the PhD student married?

kids

  Number of children less than 6 years old.

prestige

  Prestige of the graduate program.

mentor

  Number of articles published by student's mentor.

### Source

Online complements to Long (1997).

http://www.indiana.edu/~jslsoc/research_rm4cldvs.htm

### References

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.

### Examples

    ## 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")

[Package AER version 1.2-4 Index]