So this is just not correct. First off a factory can run 24/7 regardless of the shift length, which is what will determine the total productivity. Second off it assumes there are no trade offs in terms of more errors or anything else by having longer shifts. Third off it assumes that factories in different countries are going to be equally effective with each other, instead of different nations/areas within nations specializing in certain areas. It also ignores the economic benefits that come with having people in your nation having more leisure time, higher education, more time with children, etc. It's a very simplistic model that is also very incorrect.