Inflation is back, and its impact can be felt everywhere, from the grocery store to the mortgage market to the results of elections around the world. What's more, tariffs and trade wars threaten to accelerate inflation again. Yet the conventional wisdom about inflation is stuck in the past. Since the 1970s, there has only really been one playbook for fighting inflation: raise interest rates, thereby creating unemployment and a recession, which will lower prices. But this simple story hides a multitude of beliefs about why prices go up and how policymakers can wrestle them back down, beliefs that are often wrong, damaging, and have little empirical basis.