The US is really big, if there's not a mis-configured regulation, adding overseas competition won't really increase efficiency as the perfectly sperical market in a vacuum equation suggests.
Maths have nothing to do with economics. I said efficiency as a way of comparing market offer from the point of view of customers (you can picture the formula "quality/price" if you want but that doesn't mean that it is objectively & mathematically defined), meaning that prices go down and/or quality increases
mis-configured regulation
Do you have examples of good protectionist regulation ?
And no I gave a specific example with software patents so even if the US is big enough it can benefits from outside products
If we're talking about efficiency from the customer point of view, I can pay full price for American goods on Amazon but receive garbage-cheap Chinese knock-offs in the mail.
I don't even understand what you are trying to prove. That some sellers are not trust worthy ? That there will always be an intermediary taking the profit ?
And no I gave a specific example with software patents so even if the US is big enough it can benefits from outside products