Oh, The Magic of Clockwork Theory Strikes Again
If only economics worked like clockwork. A magical clockwork world wherein the number of people in a trade bloc is the same as the number of people who purchase goods and services from member nations of the trade bloc. Such a place where, for instance, 510 million people can all be counted as 510 million actual customers who actively purchase from, say, the UK.
Funnily enough, except for the history and antics of man (and woman), the real world does not work like clockwork.
510 million people do not automatically constitute 510 million paying customers for each member nation of the EU. No one is so entitled to believe they have the automatic right to count population stats this way.
The economy's health is dependent on partners that trade with it and not on the fancies of statisticians who point at numbers and conclude "There! There they are! 510 million people and all of them will purchase at least something from the UK each week"
Much better to have real and confirmed businesses plus real and confirmed people who will purchase our products and services than to have a set of numbers of prospects of which fewer than 10% might purchase goods and services from us. And, yes, I am aware it runs both sides of the Brexit debate.
So, I think you can tell what I think of your 'But, but, but there are 510 million people in the EU who earn between $5,700 and $43,454 per annum who will prefer to order sugar from us via Amazon or eBay instead of loyally walking to their local corner shop to enjoy a quick cig and a natter with their neighbours.'
That $43,454 figure is a bit too precise for my liking.
What you actually need to consider is how many people and businesses in the EU actually purchase from the UK and invest in the UK, how much of this collective transaction can EU bureaucracy interfere with, what's left of that calculation that favours the UK, how much will non-EU trade and investment bring to the UK, and what's the then total trade balance? Compare that balance with the existing balance to decide whether leaving the EU is a net benefit or gain to UK trade and industry.
Alternatively, show your lack of education and life experience, rely on hysterical loops, and try to predict economics with Clockwork Theory.
In any case, Brexit is not purely about economics.