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So, for anyone who doesn't know what the demographic transition is, a 
The demographic transition is the shift from high mortality, high fertility to low mortality, low fertility which has occurred, or is occurring, in countries worldwide over the last couple of centuries 1/n
The demographic transition is the shift from high mortality, high fertility to low mortality, low fertility which has occurred, or is occurring, in countries worldwide over the last couple of centuries 1/n
The @OurWorldInData website has excellent visualizations of the dramatic declines in mortality and fertility, for example: fertility 2/n https://ourworldindata.org/grapher/birth-rate-the-number-of-births-per-1000-people-in-the-population?stackMode=absolute&country=CHN~PRT~TUN~SWE~CHL~FRA
And here are declines in mortality (increases in life expectancy). ALL countries have experienced declines in mortality at some point since the mid 20th century 3/n https://ourworldindata.org/grapher/life-expectancy?tab=chart®ion=World
Similarly, all countries have experienced declines in child mortality in recent decades https://ourworldindata.org/grapher/child-mortality-1990-vs-2017-slope?tab=chart&stackMode=absolute&country=®ion=World
These mortality declines represent a remarkable, & remarkably rapid, shift in human demography. How remarkable? From @AnthroPsycho: 4/n
These mortality declines represent a remarkable, & remarkably rapid, shift in human demography. How remarkable? From @AnthroPsycho: 4/n
"mortality has decreased so substantially that the difference between hunter gatherers & today’s lowest mortality pops is greater than between hgs & chimps. Most of this reduction has been experienced by only 4 of the ~8000 generations that ever lived" 5/n https://www.pnas.org/content/pnas/109/44/18210.full.pdf
Ron Lee (of course) has an excellent summary of the demographic transition https://pubs.aeaweb.org/doi/pdfplus/10.1257%2F089533003772034943
James Riley offers a comprehensive overview of "The Timing and Pace of Health Transitions around the World" 6/n https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1728-4457.2005.00096.x?casa_token=8F-RF12a-IUAAAAA:5grrjn1Ze92B1LvsNN0TPSLb-uSsSaMtu6MuYUI8Ih3y2DsdWANDpIqjKtHx9_V4qJS9cYwOn73u
James Riley offers a comprehensive overview of "The Timing and Pace of Health Transitions around the World" 6/n https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1728-4457.2005.00096.x?casa_token=8F-RF12a-IUAAAAA:5grrjn1Ze92B1LvsNN0TPSLb-uSsSaMtu6MuYUI8Ih3y2DsdWANDpIqjKtHx9_V4qJS9cYwOn73u
WHY the demographic transition happened is a fascinating question. It seems (roughly) associated with the industrial revolution in Europe, though mortality may have begun declining a little earlier, as did fertility in France 7/n
Mortality reductions seem to be have driven by rising standards of living, which improved nutritional status, public health interventions and (later) improvements in medical technology 8/n https://www.nber.org/system/files/working_papers/w11308/w11308.pdf
The role of government commitment to improving population health should also be emphasised (given its continuing importance to improving population health even in low mortality populations today) 9/n https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1728-4457.2010.00353.x?casa_token=L4oMzIrVa-UAAAAA:gs36npHoB-1713VEyjxCTQHpTz5_kIz9kN9fGGAxqYowQNN2Z7sB7fseapf5mmoPf9QDJReAfwst
The fertility decline which followed undoubtedly had very complex causes & these weren't necessarily the same in all contexts 10/n
As Arland Thornton cautions us, we need to be careful not to 'read history sideways' & assume that countries which still have higher fertility & mortality are simply at earlier stages of the demographic transition that Western Europe experienced 11/n https://link.springer.com/article/10.1353/dem.2001.0039
On fertility decline, Karen Mason's 1997 paper is useful https://link.springer.com/article/10.2307/3038299
Mary Shenk, @townermc, Howard Kress & Nurul Alam's paper is more recent & includes a concise summary of the many theories which have been put forward 12/n https://www.pnas.org/content/pnas/110/20/8045.full.pdf
Mary Shenk, @townermc, Howard Kress & Nurul Alam's paper is more recent & includes a concise summary of the many theories which have been put forward 12/n https://www.pnas.org/content/pnas/110/20/8045.full.pdf
As Mason, Shenk & colleagues point out, changing economic costs & benefits of children were important in shifting fertility & fertility preferences, as were mortality decline & changing social norms around childbearing, contraceptive use and work and family life 13/n
Throwing in a personal interest, changing kin networks were likely part of the reason for changing costs & benefits of children https://www.popcouncil.org/uploads/pdfs/2011_PDRSupp_DemTranConseq.pdf#page=91
There is still surprising little info on how kin networks changed, but see @heidiColleran 14/n https://www.nature.com/articles/s41467-019-14158-2
There is still surprising little info on how kin networks changed, but see @heidiColleran 14/n https://www.nature.com/articles/s41467-019-14158-2
Changing work & family patterns were also associated with the emergence of 'male-breadwinner, female-homemaker' social norms, which may have reduced fertility preferences https://papers.tinbergen.nl/06107.pdf
Along with a 'clamping down' on the autonomy of women 15/n https://iussp.confex.com/iussp/ipc2017/meetingapp.cgi/Paper/2024
Along with a 'clamping down' on the autonomy of women 15/n https://iussp.confex.com/iussp/ipc2017/meetingapp.cgi/Paper/2024
In lower & middle income contexts, the role of, sometimes coercive, family planning policies was also important. See Mathew Connelly's book Fatal Misconception on the history of population control, tho coercion in FP programmes has not yet gone away 16/n https://www.sciencedirect.com/science/article/pii/S0277953619305258?casa_token=X2j4QTiUjrkAAAAA:rPDXNYyxNiGrZP1e0msiS4shI1kiLMYDq5f1aUHsPLazS6ncfGauqbE3Cgl8-fBKVP90sKim
So the last few centuries have seen huge change across all human populations, likely ultimately associated with changes in use of energy, including change in work & family lives & interactions with others, with profound implications for our demography /end https://www.nature.com/articles/srep00056
Oh yeah, and Hans Rosling has a great short video, with more amazing visualizations, on some of these changes "200 years which changed the world" https://www.gapminder.org/videos/200-years-that-changed-the-world/
