From the same rectal calculator he used during the VP debate.
The closest thing would be what professionals call a “WAG” which is a wild a$$ guess. Compare that to a “SWAG” which is a sophisticated wild a$$ guess based on some extremely rudimentary calculations using incomplete data.
Typically either a WAG or a SWAG will be based on experience. In Biden’s case since neither experience or data enter into the 30%, it’s simply a HUTAG which is a head up the A$$ guess. Rectal calculator is much more succinct.
I figure this: I used to estimate markets for a living; ie. how many dollars of product X sold in Russia?
Often there would be virtually no data to support an estimate. So, you would have to build an estimate from “inflowing” data. For example, refrigerator sales could have lousy numbers. But I determine the potential number of owners, a basic replacement rate, an average sales price, income ranges and then hack up an estimate.
In uncertain conditions where you manage to arrive at a number, you need to assign a confidence to it expressed by error bars; i.e., $100 million in annual sales, +/- 15%. The most common conclusion is to say, I could be right or wrong. So, I assign a 50% chance. That’s easy.
But, in HIGHLY uncertain conditions, where the data really sucks a raw egg and your estimate is hardly any better than B.S., two things happen: Your chance of being wrong increases (obviously) and the error ranges you assign to each estimate increase as well. Instead of 50% right, your chance decreases to 30% because that is where you estimate meets the next set of error bars.
So, having wrestled with estimation problems with the highest possible uncertainties, I know that saying 30% right is the same as saying “shit if I know.” Good work, Joe.