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What data do they have that supports this argument? The consensus is for a peak a bit higher. Given that 6B, 7B, 8B were all hit at consistent/decreasing interv

What data do they have that supports this argument? The consensus is for a peak a bit higher. Given that 6B, 7B, 8B were all hit at consistent/decreasing intervals of ~12 years, it would be surprising if the intervals didn’t get longer before suddenly stopping altogether

lotsofpulp 3y ago
I do not understand this comment. The interval you are referring to is time, so barring extinction or the universe’s heat death, how could that stop?
- joshuahedlund 3y ago
  I mean the intervals between population hitting a new billion (6B to 7B, 7B to 8B) They intervals have been getting shorter and shorter due to exponential growth. Obviously there will be a last such interval when population peaks (no 9B to 10B if we never hit 10B), but I would expect them to lengthen due to slowing growth rates (ex. 8 to 9 takes longer than 7 to 8) instead of the last interval being the shortest one (zoom from 7 to 8 at record speed and then never hit 9) I haven’t dived into specific rates and forecasts tho.
  - lotsofpulp 3y ago
    The article does state 8B to the peak will be 2022 to ~2050, which is longer than 12 years, although I disagree with your reasoning that the time to peak must be longer than the time from 7B to 8B. It all seems very arbitrary.
  - pixl97 3y ago
    You need to factor in the age of the population too. As large parts of your total population gets old you can have a sudden reversal.
  - throwuwu 3y ago
    It’s not a simple function of time and population. Fertility rate varies by country and more specifically by economic achievement. Population isn’t evenly distributed in either of those categories. We saw rapid gains due to China and then India modernizing. Now they are declining and peaked and its Africa’s turn but Africa is a continent made up of many countries in various states of development or regression which makes it very difficult to predict. If we take the happy path and all goes well with each country continuing to improve then they will peak quickly having the advantages of modern technology and three advanced economies investing in them.
- deleted 3y ago
  [deleted]
nsb1 3y ago
Just plain census and GDP data shows that the richer you are, the fewer children you have. As poor countries climb out of poverty, their birth rate drops. As rich countries get richer, their birth rate drops below population-sustaining levels. http://tinyurl.com/Birth-rate-per-income http://tinyurl.com/Birth-rate-per-income
- joshuahedlund 3y ago
  Yes, you are absolutely correct. This is exactly why the UN has predicted a slowing of population growth with an eventual peak of 10-11B in several decades. However this article is suggesting a much more drastic slowing and much lower peak. I am interested in the evidence or assumptions that are different between these two forecasts.
  - ZeroGravitas 3y ago
    UN projections have also been dropping over time: https://ourworldindata.org/world-population-update-2022 https://ourworldindata.org/world-population-update-2022 > Its previous release projected that the world population would be around 10.88 billion in 2100 and would not yet have peaked. > In this new release, the UN projects that the global population will peak before the end of the century – in 2086, at just over 10.4 billion people. > There are several reasons for this earlier and lower peak. One is that the UN expects fertility rates to fall more quickly in low-income countries compared to previous revisions. It also expects less of a ‘rebound’ in fertility rates across high-income countries in the second half of the century.
- thejackgoode 3y ago
  >the richer you are, the fewer children you have Not entirely true, there is a reverse-parabolic correlation [1] After certain income level, number of children per family increases. Middle class is shooting itself in the foot economically by having children, that's why there's such correlation. 1. https://www.researchgate.net/figure/Number-of-children-top-household-income-middle-and-personal-income-bottom_fig1_327921029 https://www.researchgate.net/figure/Number-of-children-top-h...

lotsofpulp 3y ago

I do not understand this comment. The interval you are referring to is time, so barring extinction or the universe’s heat death, how could that stop?

joshuahedlund 3y ago
I mean the intervals between population hitting a new billion (6B to 7B, 7B to 8B) They intervals have been getting shorter and shorter due to exponential growth. Obviously there will be a last such interval when population peaks (no 9B to 10B if we never hit 10B), but I would expect them to lengthen due to slowing growth rates (ex. 8 to 9 takes longer than 7 to 8) instead of the last interval being the shortest one (zoom from 7 to 8 at record speed and then never hit 9) I haven’t dived into specific rates and forecasts tho.
- lotsofpulp 3y ago
  The article does state 8B to the peak will be 2022 to ~2050, which is longer than 12 years, although I disagree with your reasoning that the time to peak must be longer than the time from 7B to 8B. It all seems very arbitrary.
- pixl97 3y ago
  You need to factor in the age of the population too. As large parts of your total population gets old you can have a sudden reversal.
- throwuwu 3y ago
  It’s not a simple function of time and population. Fertility rate varies by country and more specifically by economic achievement. Population isn’t evenly distributed in either of those categories. We saw rapid gains due to China and then India modernizing. Now they are declining and peaked and its Africa’s turn but Africa is a continent made up of many countries in various states of development or regression which makes it very difficult to predict. If we take the happy path and all goes well with each country continuing to improve then they will peak quickly having the advantages of modern technology and three advanced economies investing in them.
deleted 3y ago
[deleted]

nsb1 3y ago

Just plain census and GDP data shows that the richer you are, the fewer children you have. As poor countries climb out of poverty, their birth rate drops. As rich countries get richer, their birth rate drops below population-sustaining levels. http://tinyurl.com/Birth-rate-per-income http://tinyurl.com/Birth-rate-per-income

joshuahedlund 3y ago
Yes, you are absolutely correct. This is exactly why the UN has predicted a slowing of population growth with an eventual peak of 10-11B in several decades. However this article is suggesting a much more drastic slowing and much lower peak. I am interested in the evidence or assumptions that are different between these two forecasts.
- ZeroGravitas 3y ago
  UN projections have also been dropping over time: https://ourworldindata.org/world-population-update-2022 https://ourworldindata.org/world-population-update-2022 > Its previous release projected that the world population would be around 10.88 billion in 2100 and would not yet have peaked. > In this new release, the UN projects that the global population will peak before the end of the century – in 2086, at just over 10.4 billion people. > There are several reasons for this earlier and lower peak. One is that the UN expects fertility rates to fall more quickly in low-income countries compared to previous revisions. It also expects less of a ‘rebound’ in fertility rates across high-income countries in the second half of the century.
thejackgoode 3y ago
>the richer you are, the fewer children you have Not entirely true, there is a reverse-parabolic correlation [1] After certain income level, number of children per family increases. Middle class is shooting itself in the foot economically by having children, that's why there's such correlation. 1. https://www.researchgate.net/figure/Number-of-children-top-household-income-middle-and-personal-income-bottom_fig1_327921029 https://www.researchgate.net/figure/Number-of-children-top-h...