Salary Difference Between Two Genders

This data is from 2008-09 academic year from one college in the United States.

This data set lists salaries of individual professors.

The variables it includes are:

· Professor rank, differentiating between Professor, Associate Professor and Assistant Professor

· discipline, designated as A or B, indicating an theoretical field and applied fields respectively

· years since PhD, representing the number of years since their PhD was awarded.

· years in service, representing the number of years they have been a professor

· Sex, male or female

  X      rank discipline yrs.since.phd yrs.service  sex salary
1 1      Prof          B            19          18 Male 139750
2 2      Prof          B            20          16 Male 173200
3 3  AsstProf          B             4           3 Male  79750
4 4      Prof          B            45          39 Male 115000
5 5      Prof          B            40          41 Male 141500
6 6 AssocProf          B             6           6 Male  97000

ggplot(data = Salaries, aes(x = sex, y = salary)) + geom_boxplot()  + facet_wrap(~discipline, ncol = 4) + labs(title = "Prof Salary Between Discipline")

    Welch Two Sample t-test

data:  A_male and A_female
t = 3.8377, df = 25.245, p-value = 0.000741
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
 10030.19 33239.89
sample estimates:
mean of x mean of y 
110699.98  89064.94 

    Welch Two Sample t-test

data:  B_male and B_female
t = 1.2684, df = 26.341, p-value = 0.2158
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
 -4662.948 19714.649
sample estimates:
mean of x mean of y 
 118760.4  111234.5 

gf_point(salary ~ yrs.since.phd, data = Salaries, color = ~ discipline) %>%
  gf_lm() %>% 
  gf_theme(legend.position = "right") %>% 
  gf_labs(title = "Relation of Salary and Yrs.since.phd")

Based on our tests, and graphs, we observe the following:

• Male professors, on average, are paid higher than female professors in applied fields
• Professors in applied fields, on average, are paid higher than professors in theoretical fields. However, to test this, we may need to use a regression analysis