10. For a particular Big Ten university, the mean income for male faculty is $8000 higher than the mean income for female faculty. Explain how this difference could disappear.

a) Controlling for number of years since received highest degree. if male professors tend to be older and inore expenenced, relatively few female professors having been hired until recent years.

b) Controlling for college of employment. if relatively more female faculty are in low- salary colleges (Arts and Science, Education) and relatively more male faculty are in high- salary colleges (Medical School. Law. Engineering)

c) In

(a) and (b), explain how the variables mught satisfy a chain relationship =