PS. The UK economy is bigger than most EU economies put together.
I’m afraid just about every economist in the country agrees that will not be the case if we had a no-deal exit. Which is why it will never happen.
Most of these economists that you speak of either work directly for the government (the economic models that the Treasury have been using have been widely criticised), or they work for organisations that receive funding from the government and/or the EU.
The IFS is a good example as they receive funding from the government, the Economic and Social Research Council (who in turn are funded by the government ) and the EU.
These economists can't even forecast the next quarters GDP figures correctly, they didn't see the financial crash coming, and predicted that the UK would go into recession and hundreds of thousands of jobs would be lost just for voting to leave the EU.
As we know that was absolute bollix and the UK's economy has performed quite well considering the uncertainty.
The model they usually use is the Gravity Model which according to the economics professor who invented it, he said it was not only inappropriate to use for this but down right misleading & dishonest.
Our preeminent macro economist professor that was knighted for being correct (he usually is) Sir Patrick Minford iirc expects with Canada+++ an extra 1-1.5% of GDP growth per year and no deal 0-0.5%. Those who are expecting an immediate recession on No Deal will probably be disappointed due to how GDP is calculated, do you understand why?
Once we triggered Article 50 leaving is out of the UK's hand as our Parliament is in control of UK law and Brussels EU ones and this is an EU law. 29-03-2019 we leave deal or no deal, Mays suggesting otherwise is just another lie from a serial liar. At my last count over 90 Tory MPs said they are going to vote against the deal & as they realise the full horrors of the May, Hammond, Robbins & others capitulation that will rise as Tory MP pragmatism of keeping their seat always wins the day. May's total incompetence, stubborn bloody mindedness will probably cost her, her job & I sincerely hope so. Worst PM I've ever lived under that makes Major & Heath look competent in comparison.
Tories certainly seem to pick duff leaders & PMs. Gove, throwing Boris under a bus in the leadership contest is IMO the biggest cause of where we are and he by supporting May has just done the same to 17.4m leavers & the UK fishing industry which he presides over.
He is obviously currently on a double daily ration of snake oil.