On a side note, some of the cultural side effects are super interesting. For example, when I taught at a camp in China for awhile, many kids were dealing with having siblings. They had no cultural way of dealing with it. For example, in the states there are TONS of books that are like ‘big brother and baby sister’ kind of stuff, that help to give context for what siblings should do. Shows and movies will usually have sibling relationships. China doesn’t have this for obvious (state sponsored media) reasons. So more kids will be extremely culturally jarring at this point.