Purpose has become a corporate buzzword over the past decade. Leaders are embracing the idea that companies can’t just do well financially; they also have to do good for society. But how many organizations are really walking the talk? Ranjay Gulati, professor at Harvard Business School, has studied how dozens of purpose-driven companies -- from Etsy in the United States to Recruit in Japan -- simultaneously pursue profits. He argues that while we all want a win-win, leaders must also sometimes learn to make thoughtful tradeoffs. Gulati is the author of the book "Deep Purpose: The Heart and Soul of High-Performance Companies” and the HBR article “The Messy but Essential Pursuit of Purpose.”