The Five Stages of Western Fertility

By Arcotherium at Aporia, The Five Stages of Western Fertility. It is a very good summary.

1. The Western European Marriage Pattern - I have mentioned this often, usually in reference to the Hajnal Line, which notes persistent cultural differences, especially economic, to this day. It is usually considered to be in place by 1450 or so, but some historians have detected evidence of it as far back at the late 700s. It is characterised by later marriage, greater input from the marrying couple rather than simply being told by parents who their mate would be, and not all females marrying. 90% of females marrying sounds like a lot to us now, but compared to the 100% norm nearly everywhere else, it is a noticeable difference. Notably, widows who could inherit land, guild memberships, or titles no longer always chose to remarry.

2. First Demographic Transition. After the population collapses cause by the Great Plague(s), wages increased and agricultural yields were sufficient, so that infant mortality decreased and family size grew to 8, 9 or even 10 children per woman, now considered the societal maximum. Married couples started limiting later births, which had not been done before. Colonisation kept the need for children afloat, or at least created a situation where large family size was not as economically as risky.  The decrease in fertility rate occurred first in France in the late 1700s, not until the late 1800s in England, and 1900 in Germany.

3. The Baby Boom. Yes, this was not merely a bunch of horny, war-traumatised couples wanting to revert to the quiet normalcy of previous decades after WWII. Total Fertility Rate had dropped below replacement level by 1930, and the Baby Boom started then, caused by the relative wage increase and status for young men. Much that we think we know about this phenomenon turns out not to be true, and I recommend looking at the numbers and graphs for this era. I am still adjusting to this over the last coupole of years, having my favorite theories upended.

4. Second Demographic Transition - 

Within a span of six years, the United States (1973), France (1975), Germany (1970), Britain (1973), and the Nordics (1969) all went from being poised for a never-ending population explosion, of the sort that gave Paul Ehrlich nightmares, to our current path of population aging and demographic decline.

The article credits (or blames) Second-Wave Feminism and the Sexual Revolution, but considers those downstream of A) Unilateral and No-Fault Divorce, B) Affirmative Action, and C) Moral Delegitimization of Marriage. His arguments are interesting there, at least for those of us who lived through this and thought slightly different (or wildly different) things were happening. Because...weren't Contraception and abortion (and bsking would add, reliable paternity testing) the causes? 

The reason is simple: family planning is not a difficult problem. Even without the most common premodern solutions of abortion and infanticide (which were taken off the table by Christianity), Western countries were able to reduce fertility to well below replacement in the interwar period using the same techniques that have been available since people first figured out where babies come from. Even if these techniques are unreliable and inconvenient at an individual level, they are more than sufficient at the population level.

 5. Recent Collapse - Starting around 2012.

This stage is characterised by a fall from slightly below replacement-level to far below replacement-level fertility, driven by the young and the low-IQ. The proximate cause is smartphones and the internet leading to less unprotected sex, plus rising age at marriage hitting biological walls.