There's plenty of advice on how to grow into a better leader. And it takes effort to become more effective. But bad leadership gets worse almost effortlessly, says Barbara Kellerman, a Center for Public Leadership Fellow at Harvard Kennedy School. She shares real examples from the public and private sectors of how bad leaders spiral downward, and how bad followership enables that negative trend. She gives her advice for recognizing and avoiding ineffective and unethical leaders. Kellerman is the author of the new book Leadership from Bad to Worse: What Happens When Bad Festers.