I don't know if it's that simple: the very act of getting to America from Mexico has got to be cheaper and easier than from any of the other countries that you

I don't know if it's that simple: the very act of getting to America from Mexico has got to be cheaper and easier than from any of the other countries that you mentioned, surely. That is to say, because it's a lot cheaper to actually get to the USA from Mexico, more blue collar workers ("less entrepreneurial") are able to do so. If all of those other countries shared a border with the USA, only then could you really start comparing the 'entrepreneurship ratio'.