When you shop online or through an app, do you ever wonder if you’re being charged the same as someone else for the same thing? Even controlling for things like shipping address and local taxes, it turns out that today it’s not uncommon for pricing to dynamically change based on factors that may not seem fair. This is called surveillance pricing. Justin Brookman (Consumer Reports) and Eric Gardner (More Perfect Union) recently performed a study on this practice using Instacart, and the results were eye-opening.