The city of Memphis is experiencing a budget shortfall. By abolishing the rank of captain, the chief of police demonstrates that the Memphis Police Department will save $1,400,000. Unlike promotion to other ranks, which is based on merit, officers are promoted to captain automatically when they achieve thirty years of service with the department.

Captains perform the same duties as lower ranked officers, but receive higher pay because of their rank as captain. Officers who are captains were given the choice of returning to their prior lower rank and having their pay reduced, or retiring. Several officers who had been captains file suit against the city, alleging age discrimination. What must they show to establish a claim of disparate impact age discrimination?

What defenses are available to the city?

Explain. See Aldridge v. City of Memphis [2007 WL 4370707 (W.D. Tenn. Dec. 10, 2007)].