A recent paper surveyed economics instructors and asked the question, what movies do you use in class? The number one movie was Mary Poppins. In fact, it was being taught and watched for its famous scene regarding bank runs. One of our goals here is to give you Dear Planet Money Plus listeners the tools to explain as much economics about this movie to your family as possible. Whelan: I think we have to start with the most obvious thing that we're going to need to talk about, which is, of course, this famous bank run scene.