Answer:
a. The intercept terms beta0 depicts the minimum amount of salary that a person will be earning if the person is not a college graduate. beta1 depicts that if a person is a college graduate, then the salary of the person increases by \beta 1 units.
b. The error term include all other variables impacting salary of the person other than the the person being a college graduate.
c. The independent variable X will be endogenous when salary plays an important role in determination of whether a person is college graduate.
d. yes, independent variable can be endogenous in some cases when dependent variable Y is impacting the independent variable X.
e. Endogeneity can lead to relaxation of one of the important assumption of Ordinary Least Squares (OLS) which considers independent variable to be endogenous. This will lead to the problem of multi collinearity. The Simultaneous Equation model can be used in this case rather than OLS model.
Explanation: