Demonstrate that the population relationship of equation (11.1) forces the effects of race to be identical regardless of sex.

(a) Subtract equation (13.42) from equation (13.44) to derive the expected earnings difference between a black and a nonblack man.

(b) Subtract equation (13.43) from equation (13.45) to derive the expected earnings difference between a black and a nonblack woman.

(c) Compare the answers to parts a and b.

(d) Make the comparison of part a for the interacted specification of equation€(

13.48), using equations (13.53) and (13.55). Is the result the same as in part a?

(e) Make the comparison of part b for the interacted specification of equation€(

13.48), using equations (13.54) and (13.56). Is the result the same as in part b?