by Philip Tetlock & Dan Granger .Philip is the one who ran a study over 25 years to test the validity of forecasts from 284 serious experts .The result was published in 2005.
The average expert was roughly as accurate as a dart throwing chimpanzee! See more at "Analytics- the art and science of decision making".
They were no better than random guessing. They tended to have one idea and regardless of evidence that cast doubt on this idea/theory apply it.
If you were to doubt this just follow the link below to the "Cognitive Bias Cheat Sheet"
Almost certainly explains the UK public's vote for BREXIT ( we can have our cake and eat it) and the US public's vote for Donald Trump.
And worryingly, this bias is built into every business decision made so when using analytics and BI be aware of it.
We are drawn to details that confirm our own existing beliefs. This is a big one. As is the corollary: we tend to ignore details that contradicts our own beliefs.