Regardless of the field, be it economics, cookery or mechanical engineering, you can ask a pool of experts:
- How can I solve problem X? What will happen if I do nothing?
- How confident are you that the solution will be effective or the prediction will be accurate?
The problem X is the input and then you compare predictions and real outputs.
There is abundant literature on the effectiveness of economical models and the ability to make prediction and the outcomes are clear:
- Economists systematically overestimate their ability to make predictions
- There is not even a single economical theory. Economists have different schools of thought that are incompatible with each other (!)
There are countless examples of economists failing to predict the future or having wildly different opinions.