Information Analyst asked me to prove that economic forecasts are nearly always wrong. I think this is widely accepted by many leading economists - but, as they rightly say, you have to make your plans based on some forecasts, and then adjust those plans in light of reality.
Many of the project fear forecasts haven't been just inaccurate - they've been forecasts that got the direction wrong. So they forecast that unemployment would rise, but it fell; forecast that house prices would fall but they rose; forecast a recession immediately following a vote to leave, but we have now had three years of continuing growth, and so on.
If economists were like real scientists, they would provide error bars for their forecasts - they would say something like, "We expect inflation to be between 2% and 3.5% for the next year - and we'll stand up and admit we got it wrong if it falls outside that band." Fat chance of that happening - you have to treat most economic forecasts with the same scepticism that you'd apply to horoscopes.