Look at this map of total fertility : https://en.wikipedia.org/wiki/Sub-replacement_fertility#/media/File:2013_Fertility_per_woman_world_map.jpg https://en.wik

Look at this map of total fertility : https://en.wikipedia.org/wiki/Sub-replacement_fertility#/media/File:2013_Fertility_per_woman_world_map.jpg https://en.wikipedia.org/wiki/Sub-replacement_fertility#/med... If fertility is below 2.1 it's below replacement. There are not many rich countries with replacement level fertility rates. Japan's population is decreasing at ~300K a year because they don't allow much immigration. As countries become rich people leave in lower numbers. There are quite a few countries in the world that are already experiencing population decline : https://en.wikipedia.org/wiki/Population_decline https://en.wikipedia.org/wiki/Population_decline