Expert prediction accuracy is often worse than if random guesses were made.
The reason they are bad is they mistakenly think they can make an expert opinion about something that lacks regularity. In other words, when the possible outcomes are random or close to it, the result is not predictable.
For the past 3 years, we were inundated by disease model output and Expert projections about where Covid was going, or what were the best ways to control Covid. Ultimately, most predictions were wrong. Models were so bad that by October of 2022, the CDC stopped publishing their “ensemble” model forecast citing “low reliability” of the disease models.
Predictions are hard, although there may be some steps to improve results: What Research Tells Us About Making Accurate Predictions (hbr.org)
And of course, read any of Nassim Nicholas Taleb’s books on chance and probability topics.
In 1798, there were about a billion people in the world and economist Thomas Malthus predicted that overpopulation would lead to war and famine. In 1968, at 4 billion people, experts published The Population Bomb and The Limits to Growth and predicted the same thing.
Today, in 2014, there are over 7 billion people on the planet. Nevertheless, global poverty and violence are at all-time lows. Even carbon emissions are dropping (at least in the US). It seems the experts were mistaken.
One of the things that makes experts so convincing is that they exude confidence. They can talk calmly and knowledgeably about a subject, make reference to relevant facts and build a compelling logic for their case. A good expert is always impressive, but still usually wrong.
And perhaps an explanation for celebrity epidemiologists and Dr Fauci being wrong almost all the time:
So if the foxes are better forecasters, why do we only hear from the hedgehogs?
“The data shows an inverse correlation between fame and accuracy: the more famous an expert is, the less accurate their forecasts are. That happens for a very specific reason. Hedgehogs are the kind of people you see on television. The person who has one analytical idea, and who is very strong and confident in voicing his opinion – that person makes a great TV guest. A great public speaker. The person who says: ‘Well, I don’t have one big idea, but I have many ideas, and I’m thinking that there are multiple factors at work, some pointing in one direction, some pointing in the other direction…on one hand, on the other hand’ – that person makes a terrible TV guest.”