The article discusses a method to analyze the impact of big economic events on the economy. By using a specific mathematical model, researchers can identify how different factors affect each other. They found that with the right conditions, they can accurately estimate these relationships with only a few pieces of data. This new approach allows for more realistic assumptions about how errors are related and how they change over time. A test showed that this method works well, and it was applied to study the effects of a tax increase on U.S. gasoline use and carbon dioxide emissions.