The pandemic 'baby bust' in other countries

Last November, I wrote a post about the supposed lockdown 'baby boom' in New Zealand, noting that:

...while there has certainly been an increase in births, it is hardly a 'baby boom' (unless you have an extraordinarily liberal interpretation of what constitutes a boom). And, it is hard to make a case that it was caused by lockdown...

The fertility experience of other countries through the pandemic has been quite different from New Zealand's as outlined in this paper by Tomas Sobotka (Vienna Institute of Demography) and co-authors. They use Short-Term Fertility Fluctuations data from the Human Fertility Database, which includes monthly data on the number of births by country. Their paper was written in March last year, so it only includes data up to January 2021, and they exclude countries that had not yet reported December 2020 data, leaving them with 22 countries, mostly in Europe (plus the US, South Korea, and Taiwan). To overcome seasonality in the data, they compare the number of births in each month with the same month one year earlier (this short-term approach also mostly overcomes structural changes in the size of the female population of reproductive age, which won't change drastically from one year to the next). What they find is a substantial decline in the number of births across these countries as a whole, neatly summarised in Figure 14 from the paper:

A value of zero in the figure would mean no change in births from one year earlier. Clearly, there is a bigger decrease in births on average, particularly from October 2020 onwards (which would be the number of babies conceived from January 2020 onwards, when the pandemic was getting underway). However, not all countries had decreases in births (notice that Finland actually had more births over this period than twelve months earlier). And, there isn't a sudden drop-off in births on average either, so rather than the pandemic creating a sudden and large fertility shock across these countries, it appears to have mostly accelerated existing downward trends in fertility.

It would be really interesting to follow up on this work with more recent data, and data across more countries (which will have now reported births through this period and beyond). As far as I can see, Sobotka et al. have not yet done so.