@EasternStandard ,
‘Going back to major studies measuring the impact of leaving I still don’t get the inclusion of the US. We matched Germany more from 2008 to 2016 not the US so why assume we’d be matching the US with 61% rating post 2016?’
To address this! Firstly, I linked to 3 studies, which all showed the same thing (although at different levels). The Bloomberg study entirely removed the U.S, and the Cambridge econometric model used a completely different method, looking at how specific sectors were affected and then amalgamating them.
I am not an econometric expert, but I do have a decent knowledge of maths and statistics, so if there are any real experts here, please correct me!
What the NEBR study did was a complex piece of multi variable regression, which means it said let’s replace the Uk with a weighted sum of different large global economies and see which weights give the best approximation to UK growth for 10 years (say) pre Brexit. Then let’s use the same weightings post Brexit and compare it to how the UK actually did. It has validity but, like all predictions, can be flawed.
The Bloomberg study said other things changed after Brexit, such as the UK tech boom and the energy crisis, which affected Europe and the UK more than the U.S. So, it stripped the U.S out and replaced it with France and Germany and said we lost 2-4% opportunity cost (rather than 6-8%, from the NEBR study).
I do think we still had some correlation with the U.S so I am guessing maybe we lost 3-5%. Anyway, we did lose significantly. I can’t see any economists disputing that.