Jenn Dowd
@drjenndowd
Prof of Demography & Population Health @oxforddemsci.bsky.social | Mortality, Epidemiology, Infections/Immunity, Biosocial science, COVID-19. | Science Communicator 🇺🇸 in 🇬🇧. Substack:
Everyone is saying he's best known for Jurassic Park, but "I would like to have seen Montana" will live rent free in my brain forever. RIP Sam Neil 💔
Some thoughts from me on World Population Day for @prbdata.bsky.social ....let's work on actually testing those biological limits of life expectancy already! www.prb.org/news/progres... #demography @nuffieldcollege.bsky.social @oxforddemsci.bsky.social @oxpop.bsky.social
So exciting to meet Nobel Prize winner & mRNA technology pioneer Katalin Karikó yesterday, where she was awarded an honorary degree from @ox.ac.uk. Also to meet her daughter Susan Francia, an Olympic Champion Rower! 🤩 @ridhikashyap.bsky.social @oxforddemsci.bsky.social @nuffieldcollege.bsky.social
Is it a bad sign if I can’t tell if this is supposed to be ironic? #demography
"5000 women just to be on the safe side.” Really guys? The low birth rate discussions are truly going off the rails... #demography
It’s a good day in Milan when you get a special tour of @bocconi.bsky.social from the Rector himself!! #demography
I’m late, but want to Blue Sky celebrate the amazing @ridhikashyap.bsky.social & her Early Career Award from the @popassocamerica.bsky.social!! 🎉🏆👏🙌. Sometimes good things *do* happen to good people :). #demography @oxforddemsci.bsky.social @nuffieldcollege.bsky.social
@paaalpaca.bsky.social seen about town in St. Louis, but not hitting the drinks too hard (yet). 🤩🤩 @popassocamerica.bsky.social #demography
Nooooooo...... On my way to see you in St. Louis my demography peeps, but perhaps not as productive on the plane as I had hoped (or maybe more, we'll see :)).
26/ BUT as Wu points out, this approach underestimates completed fertility during postponement, because it projects trends that haven’t had the chance to recuperate. If we assume something between the “pure decline” & “pure delay” scenarios, completed fertility reaches 1.91 for the 1995 cohort.
21/ Looking back at the UpShot piece after this kerfuffle, I think the *titles* of the figures are most guilty of lacking nuance, particularly this one which mentions "catch-up." This "catch-up" does apply to the 45 year-old line, but we can't predict what will happen for 30 year olds today.
12/ The figure shows that even when the % of women w/ no children by age 30 goes up, the % by age 45 is quite consistent (as would happen w/ postponement). While Novasad points out that these lines move together when following cohorts, the size of the gap between the two lines has been growing.
11/ This is *also* true for the % of women who never have children, which was the main point of this chart. You can debate how to show these trends together (period/cohort constraint), but they are not "wrong" or misleading. These are the actual trends for women in these age groups.
10/ Again, the main thrust of the UpShot article was to say that for women who have finished their reproductive years, completed fertility has remained around 2 kids, even as the TFR fluctuated lower due to postponement. This is just... true. #demography
9/ A smaller issue w/ the reverse calculation of counts is it assumes age cohorts are the same size-this isn’t true, & some of the drops for 30-34 year olds are due to smaller cohort size. Rates would be a better way to look at this, (though still subject to period/cohort caveats).
7/ Novasad does a back of the envelope to translate these % changes into counts. Again, there isn’t anything wrong with changing the lens to absolute numbers, but it’s not the “gotcha” moment he seems to think. Extrapolating *lack* of “catch-up” from this figure is misguided for several reasons.
4/ Having thought about similar population trends *a lot*, it’s not wrong to show trends like this as a relative change—we do this a lot to get a sense of dynamics rather than levels. For example here, drawing attention to slowdowns in mortality improvements: doi.org/10.1093/ije/dyae024
3/ Looking at % change in age trends can definitely give the impression that these opposing trends have already canceled each other out (even though this is not claimed). But because the number of births is much lower in these older age groups, those % changes don’t translate into as many births.
2/ On X, Paul Novasad called out what he considered a “chart crime.”... I can kinda see his point. The article explains that shifts in births from younger to older ages mean that falling birth rates among younger women *may* eventually happen at older ages.
Measles is Back-Do you need another booster? TL:DR: Most adults will already be well protected from measles, but if you were born in certain years, you might want to consider a "better safe than sorry" dose. Read more here: jenndowd.substack.com/p/measles-is... #publichealth #medsky
Timeline cleanse… spring vibes @nuffieldcollege.bsky.social are magical.
6/ The US had the largest 5-year life expectancy deficit of any country studied: -1.73 years of life expectancy over 2020–2024, & remained 0.55 years below expected life expectancy in 2024-an important caveat to recent news of “record” life expectancy in the US that barely exceeded 2019 levels.
4/ Rather than a uniform rebound, countries diverged into four distinct mortality patterns, with varying levels of overall life expectancy loss and recovery patterns. #demography #covid #episky
3/ We show that this assumption is premature. Extending life expectancy estimates through 2024 for 34 high-income countries, we find that five years after the pandemic’s onset, 31 countries remain below their expected trajectories as projected by Lee-Carter forecasts.
2/ COVID-19 led to the largest declines in life expectancy in many high-income countries since World War II. The prevailing assumption (already embedded in major population projections) is that these losses would be transient, with a quick return to previous trajectories, like scenario A below.
1/ Has life expectancy fully recovered from the COVID-19 pandemic? In a new pre-print, we find that 31 of 34 high-income countries had still not returned to their expected life expectancy trajectories five years after the onset of the COVID-19 pandemic. www.medrxiv.org/content/10.6... #demography
Epidemiologist joy…The OG Broad Street Pump. Thanks, Dr. John Snow, for the steadfast reminder of why we do what we do! #episky #publichealth @thosenerdygirls.bsky.social @lshtm.bsky.social