More measurements by population

In class today we continued to talk a little bit about the population, but we moved into immigration. Apparently there is another type of immigration, and that is emigration. Emigration is actually the opposite of immigration, because while immigration means people entering the country, emigration means the people that are leaving the country. A fun fact that is that there is less people from Mexico, immigrating to United States, but why did they immigrate in the first place? Well there are 2 factors,  and those are called the push and pull forces. Push forces can be situations that are happening in their country like civil war, unemployment and religious or ethnic persecution etc. The pull factors, would be the country that people would immigrate to for better economic opportunity, better health service and religious and political freedom. Then the conversation turned awkward... well not too awkward. We started to talk about the total fertility rate (hopefully you can sort of see why this might of been awkward) and how for a population to remain the same the TFR, which is the average number of children per woman, has to be 2.1.  But when we looked at America's TFR, we noticed that it was under the TFR, so why is America's population going down? Well the answer of that is because of immigration. The other two countries that we looked at is Africa and Japan. Africa is way above the TFR, but the reason it's not really doing much of an effect is because if a woman were to have 5 kids, most likely only 2 would survive beyond the age of 1 years of old, and they know that, which is sad. Japan is also below the TFR, because there are a lot old people that live in Japan and they are really concerned about that because they cant find enough young people to do hard, physical jobs and there isn't much of a new population coming.