Despite the ubiquity of countless apps, social media platforms, and so-called smart devices, and even considering the renewed and welcome focus on STEM subjects, societal innumeracy remains a critical driver of bad policy and bad thinking. Almost every major issue facing today's world is made more difficult by false interpretations, incorrect assumptions, or a general misunderstanding of how numbers inform narratives and statistics shape stories. New York Times-bestselling author and math popularizer John Allen Paulos has worked for decades to educate readers on not only the formal properties of the numbers, statistics, and probabilities behind news stories, but also what they mean and how they should be interpreted. When we use mathematics to describe the social world, we are always faced with questions: What are we trying to measure or count and how do we decide whom to include, exclude, or qualify? Who's Counting features selected columns from Paulos' well-known ABC News series of the same name collected here in book form for the first time, along with updates and brand-new original essays from the author. The result is a timeless and timely examination of how better understanding data improves our thinking and decision-making. With examples from government, mass media, natural disasters, the COVID-19 pandemic, conspiracy theories, climate change, "fake news," and popular culture, Paulos shows how mathematics and logic are, along with a humble respect for truth, our most basic and reliable guides to reality.