this time, the WPP does show a population decline before the end of the century, though they still have a later and higher peak than Vollset et al.
prior to the update, the UN projections were clearly worse than the Vollset ones, now that their projections are closer together, I’m less confident which one is likely closer to the truth. but lean towards Vollset still being better and the UN not having revised down enough yet.
also, fun observation: two of the eight countries contributing most to growth in the next three decades already have shrinking birth cohort sizes, because even though cohorts are getting smaller than previous years, they’re still much larger than the elderly population which has the highest mortality rates. (India and the Philippines, though note that there is a really wide discrepancy between Philippines estimates of births and WPP estimates of births, which is wider than what the birth registration gap is purported to be)
Have you looked at the fertility rate underlying the UN projections? They’re projecting fertility rates across China, Japan, Europe, and the United States to arrest their yearly decline and begin to slowly move up back to somewhere in the 1.5 to 1.6 range.
That seems way too high because it’s assuming not just that current trends stop but that they reverse to the opposite direction of that observed. Even their “low” scenario has fertility rebounding from a low in ~2030.
This despite all those countries still have a way to go before they get to the low South Korea has reached at 0.88.
this time, the WPP does show a population decline before the end of the century, though they still have a later and higher peak than Vollset et al.
prior to the update, the UN projections were clearly worse than the Vollset ones, now that their projections are closer together, I’m less confident which one is likely closer to the truth. but lean towards Vollset still being better and the UN not having revised down enough yet.
also, fun observation: two of the eight countries contributing most to growth in the next three decades already have shrinking birth cohort sizes, because even though cohorts are getting smaller than previous years, they’re still much larger than the elderly population which has the highest mortality rates. (India and the Philippines, though note that there is a really wide discrepancy between Philippines estimates of births and WPP estimates of births, which is wider than what the birth registration gap is purported to be)
Have you looked at the fertility rate underlying the UN projections? They’re projecting fertility rates across China, Japan, Europe, and the United States to arrest their yearly decline and begin to slowly move up back to somewhere in the 1.5 to 1.6 range.
That seems way too high because it’s assuming not just that current trends stop but that they reverse to the opposite direction of that observed. Even their “low” scenario has fertility rebounding from a low in ~2030.
This despite all those countries still have a way to go before they get to the low South Korea has reached at 0.88.
See https://ourworldindata.org/explorers/population-and-demography?time=2000..latest&facet=none&country=High-income+countries~OWID_WRL~NGA~CHN~IND~Europe+%28UN%29~USA~JPN~KOR&hideControls=true&Metric=Fertility+rate&Sex=Both+sexes&Age+group=Total&Projection+Scenario=Low