Mark Rennella has given students and professionals helpful advice about writing throughout his career, most recently as a writing coach for MBA candidates at Harvard Business School. Mark earned a PhD in American history from Brandeis University and has taught literature and American history at Harvard University, the University of Miami, and the University of Tours (France). His publications include Entrepreneurs, Managers, and Leaders: What the Airline Industry Can Teach Us About Leadership, co-authored with Nitin Nohria, former dean of Harvard Business School. Mark’s books, articles, business case studies, and collaborative writing endeavors have garnered him critical praise from historians, academicians, and business leaders alike. His concept of the “One-Idea Rule” was included among HBR.org’s ten favorite management tips for 2022. He currently works as an editor for Harvard Business Publishing.