Theoretically, predicting what the economy will do depends on also predicting most other major events. For example, to know in advance how the economy would do in 2020, you would have had to predict the pandemic. You also need to predict wars, natural disasters, the weather (snowstorms affect the economy), elections, and which new laws will pass for things like stimulus bills.

Sure, sometimes it averages out. But often it's the opposite, more like catastrophic cancellation. The outcome of a close election is inherently unpredictable because large opposing forces mostly cancel out.

It's odd how, whenever we talk about what will happen next year, we forget how we were blindsided this year.