As living standards, and incomes, rise, birth rates decline, usually below replacement rate. I know of two exceptions to this: Georgia and Israel. At first glance, high Israeli birth rates might appear to find their explanation in the high birth rates of a subsection of the populace, namely Haredi Jews–often referred to as the “Ultra-Orthodox” by the media. But Haredi Jews comprise less than 15% of the Israeli population and, once more, secular Jews in Israel have a birth rate at replacement. Of course, it is exceeding difficult to avoid the impression that the aftermath of genocide has resulted in a higher birth rate for Israeli Jews. One would assume that secular Israeli Jews who reside in Israel have more of an attachment to their ethno-cultural grouping than secular Jews outside Israeli borders, if only by virtue of the fact that they live in an explicitly Jewish state.
In Georgia, birth rates were below replacement until after the Russian invasion. My friend accredits the higher Georgian birth rate to their Patriarch’s offer to baptize every third child, but I suspect it had more to do with a general sentiment that their country and culture was under attack by Russia.
Of course this all relates back to the materialism versus idealism discussion concerning the drivers of history. The materialist would say that material circumstances drive history, that two nations with similar economic circumstances would have similar behavioral and political outcomes. The idealist would say that ideas, such as a fear of lost cultural heritage or a sense of obligation towards one's ethnic group to reproduce, propel history.
The native people with which I am the most familiar, the Zuni, have a very high birth rate yet live in poverty, so they are not particularly applicable to the line of inquiry pursued by this post. More valuable would be an indigenous grouping with substantial wealth and human development. Perhaps, there are some of these in California where casinos, under legal provisions related to tribal sovereignty, have been successful in raising wealth. However, the ethnic groupings possessing ownership of these casinos are probably too small to draw conclusions from.
Of course, the elephant in the room is Ukraine which already had very low birth rates and is suffering mortality and emigration as a result of the Russian invasion. For most European countries a declining birth rate can be countered by increased immigration, albeit not without at least some political backlash. Contrary to what certain political groups would have you believe, I don't think any European country has accepted anywhere near enough migrants to endanger the continuation of its culture. But a post-war Ukraine would not be a particularly desirable destination for immigrants, and Eastern Europe already has a reputation as less than hospitable towards such newcomers.
