It seems it's not German mothers having German babies though:

https://www.destatis.de/EN/Themes/Society-Environment/Popula...

Take away over 30%(!) of births in some regions and you'll see similarly plummeting figures. It's even worse if you consider that many of those births in the "German" column are to foreign mothers with German citizenship.

To make that useful to the question you may want to show that this is different than in US, which sees also a lot of immigration. I added a comment that shows the numbers are also quite normal in UK and France. That should also be accounted for.

Here is a better chart to back this up. Data from France, UK, Germany and US:

https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?location...

Seems pretty unique to US.

Thus I conclude that most of the speculation in this thread is not backed by the facts.

there are couple of differences between EU and US which can introduce confusion:

1. EU countries sees a lot immigration from Middle East and Africa, who has more kids and there is still a cultural difference towards having kids, give some time to those people to notice the environment and you see similar trend

2. but also EU countries have stronger labor policies which impacts birth rate. Not easy to fire, even when they don't have a job, they get support from government, cheap healthcare (I pay ~250-300 EUR/month for a family, no payment for kids), free dentist until 18 years for kids.

It doesn't cancel what I have said about the impact and reasons, if same conditions exist in EU countries as well, you would see similar decline, which also means this is a political and economical issue

This may well be true. But it also may well be not true to the extend that it can explain that decline in US and the differences to similar countries. So far I’ve not seen much data to back up the alleged causality in much of this entire discussion.

sometimes discussions are just to share the opinion and disagreement, not always they contain result of research. I shared my disagreement about specific statement which says: "This decline cannot be explained by demographic, economic, or policy changes" and shared couple of economic and policy issues which might impact the birth rate.

Real reason(s) could be even different, e.g. chemicals used in foods or a plastic? we need a research. But expecting single reason is probably wrong

As the sibling post noted, most of the positive natality in Western Europe is due to immigrant mothers. And since the US has quite a strong barrier to entry for immigration they don't benefit from this effect.

[edit] Looks like in term of raw numbers, the US has much more immigrants than Germany for example. But in terms of legal immigrants there's about twice the number in Germany vs. the US for 2021 (dunno how reliable statista is though).

https://www.statista.com/statistics/199958/number-of-green-c...

https://www.statista.com/statistics/894223/immigrant-numbers...