Multiple college presidents are paid handsomely to sit on corporate boards in addition to the demands of their job. Is the practice beneficial to institutions or a personal windfall? Joseph Echevarria is a busy man. In addition to his role as president and CEO of the University of Miami and president of its affiliated health system, Echevarria sits on three corporate boards: the Bank of New York Mellon, Pfizer and Unum. Collectively, they held 7…