Price gouging in the popular imagination has a “know it when you see it” quality, but it is actually a well-developed body of law. A typical price-gouging claim has four elements. First, a triggering event, sometimes called an “abnormal market disruption,” such as a natural disaster or power outage, must have occurred. Second, in most states, the claim must concern essential goods and services. (No one cares if you overcharge for Louis Vuitton handbags during a hurricane.) Third, a price increase must be “excessive” or “unconscionable,” which most states define as exceeding a certain percentage, typically 10 to 25 percent. Finally, the elevated price must be in excess of the seller’s increased cost. This is crucial: Even during emergencies, sellers are allowed to maintain their existing profit margins. They just can’t increase those margins excessively.