Everybody has them, and they're not useless. Usually they're regularly updated when new information comes in.

I'm not saying they're useless, they're an educated guess, a valuable means of communicating an expert opinion. It can be replaced with "I have high confidence of success".

The assessment is subjective, includes personal beliefs, assumptions, etc. not just measurable objective points. The measurement uncertainty at every step and the confidence interval are disappointing despite people using percentages, suggesting confidence to the percent. A scale from 1 to 5 is most of the times just as accurate.

2 people looking at the same situation could have very different degrees of belief, which is why 2 engineers could give very different estimates. But if I say I believe the likelihood of something is 73.8% I might be more credible to the listener. Looks like I calculated, not like the guy who said "3 out of 5 we get it done".

▲

qznc a day ago | parent [-]

Cue prediction markets etc. There are mechanisms to aggregate this and have a wisdom of crowd effect.

▲

close04 a day ago | parent [-]

I'm not very familiar with how they work. Don't prediction markets give the individual gambler a boolean choice and this results in a picture of the split over the population? There's no granular option for the individual to bet 40% vs. 60% for something happening, the vote with 100% confidence that Spain wins the World Cup, they don't give 85% chance of winning.

	▲	qznc 17 hours ago \| parent [-]
		The way to express a 85% confidence is to size your investment accordingly. For example, if the market is at 75%, then you buy yes-shares until the price is at 85%. If the market is at 90%, then buy no-shares instead until the price is down to 85%.