Two good friends, Mojo Nixon and Natalie Mer chant, grew up together, went to the same schools, ranked identically in IQ testing, excelled in every subject, and went on to earn Ph.D.'s. Natalie became a professor of finance; Mojo became a professor of English. Both teach at the same college. Natalie earns $55,000, while Mojo earns $37,000. Is there economic injustice in this story? Perhaps discrimination? How can you explain the income differential?