 Marginal propensities to consume and save. Economics is a broad field just like medicine. You want your heart surgeon working on an orthopedic knee replacement? I've got news for you. He'll be like, brother, I have no idea how to do that. I'd have to watch it on YouTube. Yeah, but you're a doctor. Yeah, but that's not what I do. It's called the knowledge problem. The left does it all the time.