There are no real hard facts just forecasts and opinions. There isn't an economic body in the world that hasn't predicted that the outcome on the economy would be negative, at least in the short to medium term. In the long term 10+ years there may be a benefit, but predicting economies that far in the future isn't much different than reading entrails.
The lack of real facts has an impact on the debate. The pro-leave faction has devolved into tub thumping patriotism and xenophobia. The remain faction doesn't have anyone with any charisma or presence to counter this.
THIS
I have attended a few talk, not by politicians. Instead an economist, a professor of law, a security expert, and an expert on britiain and the EU who has written the book on it.
Most of them say, with their heart they want to be OUT. A free Britain, a Britain without other people telling us what to do, standing on our own two feet. But with their head, the benefits are minimal, and the potential for negative impact is high. They were clear that it is the potential negative effects as no-one really knows, but they felt it was too big a gamble to take.
The reality post-BREXIT would be that the EU would still tell us what to do. Anything you want to sell in to the EU, still has to meet EU Standards. We just would not have a say in what those standards would be.
The numerous trade deals we have for various countries around the globe would be invalid, as we have signed up to them through the EU. That would take a lot of re-negotiating.
On the EU trade deal. The question that no pro-Leave person can answer is - Why would they EU give Britain a better deal once we have left? If they agree to it, won't other countries request the same. Where is the impetus for the EU to do that.
Also, what sort of economy would we be post-BREXIT. I have seen talk of Signapore or Hong Kong. But that involves living in a de-regulated economy and relying a lot on....cheap immigration! So if that were the new basis of the economy, we would need more immigrants at the lower job level.
From a selfish point of view, if the sterling drops, which it is roundly expected to do prost-Brexit, interest rates will go up. I am happy with my mortgage payments as they are. I don't want even 1 year of high payments, worse still 5 years.