How Do You Predict What's Going to Happen?

You can never predict everything that's going to happen. Part of the prudent process would be to include whatever you can possibly include and control for in that model initially. Any of these things coming out of these models are really ranges we don't know for sure, but we do know with some confidence what kind of range we should supply. And a bigger range means less confidence, but you could argue that any type of information is better than nothing.