In the U.S. alone, more than $400 billion are donated to charity each year—equivalent to two percent of American GDP. This generosity is wonderful, but these gifts don’t do nearly as much good as they could. In recent years, researchers have started studying the effectiveness of different charities, just as investors study the effectiveness of different companies. These researchers ask questions like: How much money does it cost for this charity to save someone’s life? The answers are stunning. Charity experts estimate that the most effective charities are about 100 times more effective than typical charities. For example, you can do more good by donating $100 to a highly effective charity than by donating $10,000 to a typical charity. Shermer and Greene discuss effective altruism, evidence-based philanthropy, and GivingMultiplier’s unique model for maximizing charitable impact. They explore moral judgment theories, from deontology to consequentialism, and delve into complex topics like donor fatigue, public vs. private solutions, abortion, capital punishment, and political polarization. Greene shares practical insights into addressing societal divides and inspiring collective action. Joshua Greene is a Professor of Psychology at Harvard, where he teaches “Evolving Morality: From Primordial Soup to Superintelligent Machines,” one of the university’s most popular courses. He is also the author of Moral Tribes: Emotion, Reason, and the Gap Between Us and Them, which integrates moral philosophy, psychology, and neuroscience to explain the underlying causes of modern conflict. Josh’s latest applied research has led to novel, evidence-based strategies for reducing political animosity and inspiring thousands of people to support nonprofits addressing extreme poverty, climate change, and other pressing societal issues. His new organization is GivingMultiplier.org.