[nine_one_4]

If we liken the people of the poorest, most corrupt, most crime infested country or society on earth to the dirtiest or most polluted water available on earth and people from the second worst country in terms of poverty, corruption and crime to the second most polluted water on earth and so on all the way up to likening the people from the richest, least corrupt and least criminal society to the cleanest water available on earth, when would it be wise for countries to let in massive numbers of people from poorer more corrupt countries? Can the emigration of millions of people from poorer countries to wealthier countries and the resulting consequences for the level of prosperity, crime rate, level of corruption etc. of the host country be analyzed similar to how one would mathematically analyze the resulting purity of water in a mixing problem typical of what you would solve in a differential equations course or is it more complex than that? And are the qualities of a country a result of the qualities of its average citizen?