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The end of the article raises a point in terms I hadn't quite thought about it before. Yes, the birth rate is decreasing, but the survival rate of young childr

by smeej 3y ago

The end of the article raises a point in terms I hadn't quite thought about it before. Yes, the birth rate is decreasing, but the survival rate of young children has also never been better. That would mean the number of children each woman is raising to adulthood is changing slower than the birth rate. It cites Niger as an example where more than 1 in 5 children were dying before the age of 5, and now the number has dropped closer to 1 in 10. So as to avoid dealing with fractional numbers of children, I'm going to use an example of ten mothers, but doesn't this mean that, for a group of ten mothers to have 40 children survive to adulthood, they previously needed to give birth 50 times, but now they only need to give birth 44 times? So the birth rate can fall by more than 10% without affecting the total population in a situation where the childhood survival rate increases? What would you call a statistic about "children who made it to adulthood, per adult woman"? It sounds like, at least in some countries, women aren't "choosing to have smaller families" as much as "not having to give birth an additional time to bring the family number back to what it would have been had they not lost a child."

wayfinder 3y ago
Isn’t that statistic basically the population growth rate?
- smeej 3y ago
  Not really, because the population growth rate also includes adults dying later. If someone dies at 75 instead of 80, their mother isn't going to consider giving birth another time to maintain the family size, but that person still gets counted in the total population size for five extra years. I'm wondering how we could separate out these two situations.
  - pixl97 3y ago
    That's just the life expectancy metric.
    - smeej 3y ago
      Sure, but how do you separate out the change in life expectancy metric for people who do survive childhood from the ones who don't? Basically the stat I'm looking for is "number of children per family that survive to adulthood," because I want to compare the change in that to the change in birth rate.
      - pixl97 3y ago
        That is "total fertility rate" >The total fertility rate in a specific year is defined as the total number of children that would be born to each woman if she were to live to the end of her child-bearing years and give birth to children in alignment with the prevailing age-specific fertility rates. It is calculated by totalling the age-specific fertility rates as defined over five-year intervals. Assuming no net migration and unchanged mortality, a total fertility rate of 2.1 children per woman ensures a broadly stable population. Together with mortality and migration, fertility is an element of population growth, reflecting both the causes and effects of economic and social developments. The reasons for the dramatic decline in birth rates during the past few decades include postponed family formation and child-bearing and a decrease in desired family sizes. This indicator is measured in children per woman.
        smeej 3y ago
        That's still not quite what I'm looking for. I want to compare that stat to the total number of children the average woman raises to adulthood, to understand better how an improved survival rate affects the number of children a woman gives birth to. I'm looking for the term itself because I want to look up existing research on the subject, but can't figure out what to search for because I don't know what that stat would be called.
euroderf 3y ago
Falling birth rates lag falling child mortality by a generation or two. Lived experience is the key. I think also that's why historically, wars have come in (roughly) 50-year cycles.
paulddraper 3y ago
> What would you call a statistic about "children who made it to adulthood, per adult woman"? Infant mortality rate, under-5 mortality rate, child mortality rate. Under-5 is the most common measure.
- xboxnolifes 3y ago
  That would be part of it. You'd have to multiply the mortality rate by the birth rate, right?
  - paulddraper 3y ago
    For population growth? Yeah I was responding to "children who made it to adulthood, per adult woman"
- smeej 3y ago
  I'm referring to the inverse of this, though. I'm looking for the number of children per family who do survive childhood.
  - paulddraper 3y ago
    Okay so invert the number
    - smeej 3y ago
      I want to do research on the stat and what people have learned about it. I'm specifically trying to find out what that stat would be called so I can search for it in existing research, not just how to calculate it.
markwkw 3y ago
These two effects are not similar in scale. Fertility across the globe is falling by a lot. Africa went from 6.7 to 4.2 in a span of 50 years. Asia went from 6 to 1.9. Anywhere but least developed countries child mortality is low, such that fertility replacement level is estimated at 2.1 (vs 2.0 if everyone survived until reproductive age). We used to have 5-6 kids, with one dying if you were a bit unlucky (statistically speaking). Now we have 2 or less.
- smeej 3y ago
  Sure, it's not the full cause of the fall in birth rates. Somehow it had just never occurred to me that of course any family that has an "ideal size" is going to have fewer births if all the children survive than it will if one or more of them die, and now I'm trying to figure out what terms I would even look up to find out how much of the effect could be attributed to that. In other words, how much of the decline in birth rate is due to parents reaching their ideal family size without the death of any children? I'm reasonably sure it's small, but are we talking <1% small or 10% small? Edit: typo
dooglius 3y ago
Well, the overall rates still need to be at least 2 to sustain population.
autoexec 3y ago
> Yes, the birth rate is decreasing, but the survival rate of young children has also never been better. Not in the US. The infant mortality rate is increasing. https://apnews.com/article/infant-deaths-us-cdc-mortality-c808796da0415b6ecc0629938421e1b5 https://apnews.com/article/infant-deaths-us-cdc-mortality-c8...
- advisedwang 3y ago
  That report [1] shows an increase from 5.44 per 1000 to 5.60. But if you look at the longer timeline [2] you can see that its a general downward trend with the occasional slight uptick. The increase this year just looks like random fluctuation, not a reversal. [1] https://www.cdc.gov/nchs/data/vsrr/vsrr033.pdf https://www.cdc.gov/nchs/data/vsrr/vsrr033.pdf [2] https://www.cdc.gov/nchs/data/nvsr/nvsr72/nvsr72-11.pdf https://www.cdc.gov/nchs/data/nvsr/nvsr72/nvsr72-11.pdf

by smeej 3y ago

wayfinder 3y ago

Isn’t that statistic basically the population growth rate?

smeej 3y ago
Not really, because the population growth rate also includes adults dying later. If someone dies at 75 instead of 80, their mother isn't going to consider giving birth another time to maintain the family size, but that person still gets counted in the total population size for five extra years. I'm wondering how we could separate out these two situations.
- pixl97 3y ago
  That's just the life expectancy metric.
  - smeej 3y ago
    Sure, but how do you separate out the change in life expectancy metric for people who do survive childhood from the ones who don't? Basically the stat I'm looking for is "number of children per family that survive to adulthood," because I want to compare the change in that to the change in birth rate.
    - pixl97 3y ago
      That is "total fertility rate" >The total fertility rate in a specific year is defined as the total number of children that would be born to each woman if she were to live to the end of her child-bearing years and give birth to children in alignment with the prevailing age-specific fertility rates. It is calculated by totalling the age-specific fertility rates as defined over five-year intervals. Assuming no net migration and unchanged mortality, a total fertility rate of 2.1 children per woman ensures a broadly stable population. Together with mortality and migration, fertility is an element of population growth, reflecting both the causes and effects of economic and social developments. The reasons for the dramatic decline in birth rates during the past few decades include postponed family formation and child-bearing and a decrease in desired family sizes. This indicator is measured in children per woman.
      - smeej 3y ago
        That's still not quite what I'm looking for. I want to compare that stat to the total number of children the average woman raises to adulthood, to understand better how an improved survival rate affects the number of children a woman gives birth to. I'm looking for the term itself because I want to look up existing research on the subject, but can't figure out what to search for because I don't know what that stat would be called.

euroderf 3y ago

Falling birth rates lag falling child mortality by a generation or two. Lived experience is the key. I think also that's why historically, wars have come in (roughly) 50-year cycles.

paulddraper 3y ago

> What would you call a statistic about "children who made it to adulthood, per adult woman"? Infant mortality rate, under-5 mortality rate, child mortality rate. Under-5 is the most common measure.

xboxnolifes 3y ago
That would be part of it. You'd have to multiply the mortality rate by the birth rate, right?
- paulddraper 3y ago
  For population growth? Yeah I was responding to "children who made it to adulthood, per adult woman"
smeej 3y ago
I'm referring to the inverse of this, though. I'm looking for the number of children per family who do survive childhood.
- paulddraper 3y ago
  Okay so invert the number
  - smeej 3y ago
    I want to do research on the stat and what people have learned about it. I'm specifically trying to find out what that stat would be called so I can search for it in existing research, not just how to calculate it.

markwkw 3y ago

These two effects are not similar in scale. Fertility across the globe is falling by a lot. Africa went from 6.7 to 4.2 in a span of 50 years. Asia went from 6 to 1.9. Anywhere but least developed countries child mortality is low, such that fertility replacement level is estimated at 2.1 (vs 2.0 if everyone survived until reproductive age). We used to have 5-6 kids, with one dying if you were a bit unlucky (statistically speaking). Now we have 2 or less.

smeej 3y ago
Sure, it's not the full cause of the fall in birth rates. Somehow it had just never occurred to me that of course any family that has an "ideal size" is going to have fewer births if all the children survive than it will if one or more of them die, and now I'm trying to figure out what terms I would even look up to find out how much of the effect could be attributed to that. In other words, how much of the decline in birth rate is due to parents reaching their ideal family size without the death of any children? I'm reasonably sure it's small, but are we talking <1% small or 10% small? Edit: typo

dooglius 3y ago

Well, the overall rates still need to be at least 2 to sustain population.

autoexec 3y ago

> Yes, the birth rate is decreasing, but the survival rate of young children has also never been better. Not in the US. The infant mortality rate is increasing. https://apnews.com/article/infant-deaths-us-cdc-mortality-c808796da0415b6ecc0629938421e1b5 https://apnews.com/article/infant-deaths-us-cdc-mortality-c8...

advisedwang 3y ago
That report [1] shows an increase from 5.44 per 1000 to 5.60. But if you look at the longer timeline [2] you can see that its a general downward trend with the occasional slight uptick. The increase this year just looks like random fluctuation, not a reversal. [1] https://www.cdc.gov/nchs/data/vsrr/vsrr033.pdf https://www.cdc.gov/nchs/data/vsrr/vsrr033.pdf [2] https://www.cdc.gov/nchs/data/nvsr/nvsr72/nvsr72-11.pdf https://www.cdc.gov/nchs/data/nvsr/nvsr72/nvsr72-11.pdf