For decades, dollars have been the world's common financial language. Central banks everywhere hold dollars as a way to safely store their wealth. Countries, businesses, and people use it to trade; around 90% of all foreign exchange transactions involve dollars. It's the world's money, the world's "reserve currency."But what if that is changing? What if the world stops seeing the dollar as safe? Today on the show, what is a "reserve currency"? Why is it the dollar? And if the dollar falls from favor, what will replace it?This episode of Planet Money was produced by Emma Peaslee with help from James Sneed. It was edited by Marianne McCune with fact checking help from Sierra Juarez. It was engineered by Kwesi Lee. Alex Goldmark is our executive producer. The Dollar Trap by Eswar PrasadExorbitant Privilege by Barry EichengreenOur Dollar. Your Problem by Ken RogoffFind more Planet Money: Facebook / Instagram / TikTok / Our weekly Newsletter.Listen free at these links: Apple Podcasts, Spotify, the NPR app or anywhere you get podcasts.Help support Planet Money and hear our bonus episodes by subscribing to Planet Money+ in Apple Podcasts or at plus.npr.org/planetmoney.Music: NPR Source Audio - "Virtual Machine," "Fake Blood" and "Successful Secrets"Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy