What you need is enough people with access to education, and enough of a safety net to risk innovation. Given that there are a lot of people in the world who s

What you need is enough people with access to education, and enough of a safety net to risk innovation. Given that there are a lot of people in the world who still have no access to a university level education and are living paycheck to paycheck, I'd speculate that you could possibly get away with half or even less the 2018 population in order to maintain 2018 technology in a system that actually worked on merit.