monthly French fertility rates from 1861 to 2023 (more in comments) [OC]
Warm colors = higher fertility rates, cool colors = lower fertility rates. 3 major wars (Franco-Prussian War, World War I, World War II) stand out, as do more recent events like COVID.
French fertility trends by month from 1861 to 2023. Warm colors = higher fertility rates, cool colors = lower fertility rates. More charts posted here as comments since Reddit is giving me a hard time with image uploads.
Data is (births in month) / (number of days in the month) / (number of women age 15-44) * 100k
The “general fertility rate” is usually expressed as the number of live births per 1000 women age 15-44 in a given year; I scaled the daily fertility rate per 100k women to get whole numbers. 15-44 is the age range used by the UN. I aggregated single-year age groups from the Human Mortality Database and linearly interpolated between censuses.
Three major wars stand out: the Franco-Prussian War (1870-1871), World War I (1914-1918), and World War II (1939-1945). France had its own post-war baby boom after WWII, which has had echoes in the early 1980s and around 2010. Even at this scale you can see the effects of COVID in late 2020 and early 2021. I’m curious to hear what other patterns you see (I’m not an expert on French history).
Inspired by a post by Aaron Penne from 8 years ago on monthly USA birth rates. Data availability has improved drastically since then, yet `matplotlib` has not.
I used the `turbo` colormap in matplotlib because it was designed to make subtle value differences visible… does it work here?
I’m working on a series of these heatmaps for other countries and am looking for feedback on the approach, formatting, labeling, etc. I’ll post the code and data in a GitHub repository soon, probably with another country’s heatmap tweaked as per your suggestions.
aar0nbecker on
Here’s a heatmap covering recent fertility trends, from 1975 to 2023:
I’m also experimenting with a “wrapped” heatmap for countries with very long time series (like France). What do you think of this version? The color scale is still the same for every row.
This is really interesting. You can clearly see WWI and WWII. Any insight into what the blip on the radar in 1871 is? I’m not up on my European History.
aar0nbecker on
This heatmap shows the seasonality of births from 1861 to 2023. The seasonality heatmap shows the percentage of each year’s births in each month, but I scaled the monthly averages to a 30-day month and the annual average to a 360-day year so that February had a fighting chance. Births seem to have shifted from spring to summer/fall roughly since the introduction of birth control.
This heatmap shows the seasonality of births from 1975 to 2023 (percentage of annual births in each month, normalized to a 30-day month and 360-day year). Births seem to have shifted from spring to summer/fall roughly since the introduction of birth control:
This line chart shows the overall most and least common birth months since 1861 compared to other months and the yearly average. Before the mid-1970s April was usually the most common birth month:
This violin plot shows the distribution of monthly birth rates relative to trailing 12-month average since 1975. Births tend to rise in spring and peak in summer/early fall (except August, vacation month):
Interesting that birth rates didn’t decline nearly as much during WWII as WWI. Probably because it was the country was occupied rather than having all the men on the front?
Agent10007 on
If anyone wonders, the Veil law in France was passed in 1974, making the contraceptive pill reimbursed by social security.
uthinkther4uam on
“I wonder what happened in the 1910’s and 40’s?”
theservman on
I’m surprised that the WWI dip is bigger than the WWII dip. I guess because France was occupied as opposed to actively on the front lines. While there was fighting all over, everyone was home at night…
Lysol3435 on
WW2 – na. I’m fucking my way through it
lucianw on
That’s a fascinating chart, and beautifully presented. Thank you.
16 Comments
French fertility trends by month from 1861 to 2023. Warm colors = higher fertility rates, cool colors = lower fertility rates. More charts posted here as comments since Reddit is giving me a hard time with image uploads.
Data is (births in month) / (number of days in the month) / (number of women age 15-44) * 100k
The “general fertility rate” is usually expressed as the number of live births per 1000 women age 15-44 in a given year; I scaled the daily fertility rate per 100k women to get whole numbers. 15-44 is the age range used by the UN. I aggregated single-year age groups from the Human Mortality Database and linearly interpolated between censuses.
Three major wars stand out: the Franco-Prussian War (1870-1871), World War I (1914-1918), and World War II (1939-1945). France had its own post-war baby boom after WWII, which has had echoes in the early 1980s and around 2010. Even at this scale you can see the effects of COVID in late 2020 and early 2021. I’m curious to hear what other patterns you see (I’m not an expert on French history).
Inspired by a post by Aaron Penne from 8 years ago on monthly USA birth rates. Data availability has improved drastically since then, yet `matplotlib` has not.
I used the `turbo` colormap in matplotlib because it was designed to make subtle value differences visible… does it work here?
Source: [Human Mortality Database](https://www.mortality.org/)
Tools: python, polars, matplotlib
I’m working on a series of these heatmaps for other countries and am looking for feedback on the approach, formatting, labeling, etc. I’ll post the code and data in a GitHub repository soon, probably with another country’s heatmap tweaked as per your suggestions.
Here’s a heatmap covering recent fertility trends, from 1975 to 2023:
https://preview.redd.it/ppwmucd7bn0g1.png?width=3211&format=png&auto=webp&s=95628d57d8b82c1ba426118b4e8fba30e4b2af30
I’m also experimenting with a “wrapped” heatmap for countries with very long time series (like France). What do you think of this version? The color scale is still the same for every row.
https://preview.redd.it/y3ddrd7jbn0g1.png?width=3900&format=png&auto=webp&s=5785c39e5e4c34c0a899c182d35ceb7092bd2d0f
This is really interesting. You can clearly see WWI and WWII. Any insight into what the blip on the radar in 1871 is? I’m not up on my European History.
This heatmap shows the seasonality of births from 1861 to 2023. The seasonality heatmap shows the percentage of each year’s births in each month, but I scaled the monthly averages to a 30-day month and the annual average to a 360-day year so that February had a fighting chance. Births seem to have shifted from spring to summer/fall roughly since the introduction of birth control.
https://preview.redd.it/69h29r5qbn0g1.png?width=9243&format=png&auto=webp&s=68866cf79f5086399a35251d054f8c2687eca565
This heatmap shows the seasonality of births from 1975 to 2023 (percentage of annual births in each month, normalized to a 30-day month and 360-day year). Births seem to have shifted from spring to summer/fall roughly since the introduction of birth control:
https://preview.redd.it/714xhl1wbn0g1.png?width=3188&format=png&auto=webp&s=bd28d649bc486797c89b59520a12d80d969bb225
This line chart shows the overall most and least common birth months since 1861 compared to other months and the yearly average. Before the mid-1970s April was usually the most common birth month:
https://preview.redd.it/ds468ph1cn0g1.png?width=4152&format=png&auto=webp&s=3b71b9e9b011ed7238b2bb2323369ba321c9024f
Since 1975 the most common birth month has been July, a shift from the spring months seen earlier:
https://preview.redd.it/bfgarxg5cn0g1.png?width=4152&format=png&auto=webp&s=5d2a14ce52bc89b13803587bbc1d2c38d8e03077
This violin plot shows the distribution of monthly birth rates relative to trailing 12-month average since 1975. Births tend to rise in spring and peak in summer/early fall (except August, vacation month):
https://preview.redd.it/7sm95mn9cn0g1.png?width=4167&format=png&auto=webp&s=4219e717c5ee4f830bc84323e3094b178d3436b9
Interesting that birth rates didn’t decline nearly as much during WWII as WWI. Probably because it was the country was occupied rather than having all the men on the front?
If anyone wonders, the Veil law in France was passed in 1974, making the contraceptive pill reimbursed by social security.
“I wonder what happened in the 1910’s and 40’s?”
I’m surprised that the WWI dip is bigger than the WWII dip. I guess because France was occupied as opposed to actively on the front lines. While there was fighting all over, everyone was home at night…
WW2 – na. I’m fucking my way through it
That’s a fascinating chart, and beautifully presented. Thank you.
The World Wars made a huge impact in the data.