Entry-level job preferences. Benefits Quarterly periodical publishes a study of entry-level job preferences.

A number of independent variables are used to model the job preferences (measured on a 10-point scale) of business school graduates. Suppose stepwise regression is used to build a model for job preference score (y) as a function of the following independent variables:

x1 = e 1 if flextime position 0 if not x2 = e 1 if day care support required 0 if not x3 = e 1 if spousal transfer support required 0 if not x4 = Number of sick days allowed x5 = e 1 if applicant married 0 if not x6 = Number of children of applicant x7 = e 1 if male applicant 0 if female applicant

a. How many models are fitted to the data in step 1?
Give the general form of these models.

b. How many models are fitted to the data in step 2?
Give the general form of these models.

c. How many models are fitted to the data in step 3?
Give the general form of these models.

d. Explain how the procedure determines when to stop adding independent variables to the model.

e. Describe two major drawbacks to using the final stepwise model as the “best” model for job preference score (y).