Research Brief by Kip Hansen — 23 November 2024 – 700 words
A very interesting paper has been published by Anup Malani and Ari Jacob, both out of the National Bureau Of Economic Research in Cambridge, MA, USA, “a private, nonprofit organization that facilitates cutting-edge research on and analysis of major economic issues.” ( The views expressed in the paper are those of the authors and do not necessarily reflect the views of the NBER.)
The paper is titled “A NEW MEASURE OF SURVIVING CHILDREN THAT SHEDS LIGHT ON LONG-TERM TRENDS IN FERTILITY” [ or as .pdf here ].
What long-term trends in fertility? This [ blue trace is 1950 through 2023]:
The authors start with this:
“The world has experienced a dramatic decline in total fertility rate (TFR) since the Industrial Revolution. Yet the consequences of this decline flow not merely from a reduction in births, but from a reduction in the number of surviving children. We propose a new measure of the number of surviving children per female, which we call the effective fertility rate (EFR). EFR can be approximated as the product of TFR and the probability of survival.”
“We specialized EFR to measure the number of daughters that survive to reproduce (reproductive EFR) [EFRR] and the number children that survive to become workers (labor EFR) [EFRL].”
“We use three data sets to shed light on EFR over time across locations. First, we use data from 165 countries between 1950-2019 to show that one-third of the global decline in TFR during this period did not change labor EFR [EFRL], suggesting that a substantial portion of fertility decline merely compensated for higher survival rates.”
And the result is that:
“In this paper we offer a new measure of the number of surviving children per reproductive age female. It is motivated by economic models, which posit that households care about the number of children who survive—not merely the number who are born. It can also be used to test those models. Our measure of surviving children can be specialized—via EFRL and EFRR—to measure growth in the population that produces or that reproduces, respectively.”
This figure from the paper gives the best graphical representation of their point:
Why should we care?
Worldwide and National Fertility Rates are predictive of future population totals and very important for future economic conditions. Falling populations have led, in some countries, to shortages of workers to keep up industrial production.
The United Nations has been making a great deal of fuss about Total Fertility Rate and I have written about the issue in “Population Bombing”. The popular press hack on about both excessive population growth and population degrowth.
But here is my thought after reading this new paper:
Maybe we have been looking at the wrong statistic. Malani and Jacob suggest that a better way of looking at fertility, from a demographic viewpoint, is to look at their two “new and improved” statistics: Effective Reproductive Rate – Labor and Effective Reproductive Rate – Reproductive.
In the advanced nations, these are running far below the necessary 2.1 replacement rate but have stabilized (no longer dropping) since about 1990. This gives a different picture than the older Total Fertility Rate.
So what?
Analyses of modern societal problems are often based on statistics about or related to the perceived problem. The statistic(s) favored by policy makers are, more often than not, not measures of the problem itself but of something merely related to the problem.
At this website, the statistic most favored by policy makers for the generalized topic here, Climate Change, is one of the many “global average surface temperature” indexes. That statistic is touted in every COPxx meeting as being/going too high.
However, there are well-reasoned opinions that view that index, that statistic, as flawed or even concocted. Some opinions view that statistic as a non-scientific “apples and oranges” mishmash.
Others are perfectly willing to accept statistic in current use but opine that it is not the measure of “Climate Change”.
The discussion points for today:
1. World fertility rates – a problem, a solution, an improvement, and/or looming disaster (in which direction)? None of these?
2. Are ANY of the so-called Global Average Surface Temperature indexes appropriate to stand as a measure of Global Climate change?
3. Do you know of any other fields of research that are based on what you think is the wrong metric/measure/statistic?
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Author’s Comment:
The idea that TFR is not an appropriate or the most appropriate statistic for population growth studies is intriguing. And has led to the question: are we using the right and/or best statistic as an/the indicator for other societal problems? Are some that we commonly use appropriate in any way whatever or are some simply wrong from the start?
I do have personal opinions about GAST and its indexes, previously expressed on the pages here at WUWT.
Overall, maybe we should be rebooting a lot of topics by asking: “Are we using the right measure of the problem?” Give examples if you have them.
Thanks for reading.
# # # # #
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What is probably obvious is that EFR daughters and EFR workers are not independent variables. I couldn’t guess what percentage of women become both mothers and workers but I suspect that it is high these days.
Yes, most mothers do put in a great deal of necessary home labor virtually every day, often without appropriate recognition, but that doesn’t seem to be part of the workers in the formulas. Workers, however, includes those mothers that have a money making job whether that be working for money from home or working for money away from home.
“Yes, most mothers do put in a great deal of necessary home
labor virtually every day, often without appropriate recognition.”
___________________________________________________
Divorced women who didn’t work outside of the home get minimum social security.
They aren’t 2nd class citizens but the social security system treats them like they are.
Both fertility statistics seem similar. Both are worthless since fertility matters for a nation but a global average is irrelevant
The global average temperature statistic is a useful one, but a local average temperature would be more useful, especially if shown for each season.
Statistics are not the primary problem
The problem is interpreting them
A rising GAT is said to be bad news
But based on the first 50 years of global warming, it has been good news
There are many negative claims made abot a declining population. Japan has had a declining population since 208. If that caused any problems, they are not obvious.
One claim in this article is false:
“Falling populations have led, in some countries, to shortages of workers to keep up industrial production.”
Jobs that most native Americans do not want are being filled by immigrants, robots, other automation and outsourcing to Asia.
The economy grew an average of 3.3% under Biden (versus 1.6% under Trump 1.0) and unemployment is currently low.
A huge shortage of workers was only a temporary problem caused by Covid. Job openings are currently low in the US:
. United States Job Openings NSA
Does Richard just automatically score downvotes?
IMHO he makes good valid points in this case.
It’s because he accurately quoted the growth figures for Biden and Trump.
Of course, Covid had an impact. That should have been mentioned.
But it would have made difference. the Trump Fanatics cannot bear any disparagement of their Messiah. They view it as blasphemy.
I’m so looking forward to the US pulling out of NATO and telling the UK, about that ‘Special Relationship’, “we’re just not that into you”.
The way your country is being run into the Gulag by Keir Stalin, how dare you?
Richard works hard for his well-deserved downvotes.
I get automatic down votes and usually a nastygram from BeNasty 2000. It’s a WUWT tradition.
At this website just saying CO2 is a greenhouse gas that causes global warming gets the Peanut Galler overstimulated.
For 28 years I have advocated for MORE CO2 in the atmosphere because the warming effects are mild and pleasant, while plants love more CO2.
There are conservative Nutters who claim CO2 does nothing while leftist Nutters claim CO2 does everything.
They object to honest science: CO2 is a weak greenhouse gas that does no harm
Honest Climate Science and Energy
Manufacturing jobs were more desired when they were union jobs that paid very well.
In 2023 just 7.9 percent of manufacturing workers were union members, 1970 was over 25% and the sector employed roughly 18 million workers, or 31 percent of private sector employment.
You get down votes because you can not resist the impulse to include insults.
As well as half truths that imply false claims.
There are several commenters who can’t avoid schoolyard insults and continuing arguments, yet they don’t get downvotes. The problem is Richard often makes good sense, whereas the others …
I think your winning personality has something to do with the downvotes.
But it’s not just an automatic downvote when people see your name on a comment. Look at what you posted. More people wanted manufacturing jobs when they paid better. Is that supposed to be profound? Have you uncovered a lost economic principle? What do you think this proves?
Your nasty comment proves you are a dork
Hardly nasty, Richard.
“You get down votes because you can not resist the impulse to include insults.”
And there it is.
Oh dear, poor RG…. Another FAILURE to answer the questions..
… other than with ego-driven mindless bluster.
I downvoted just to be polite. I liked your post.
Do you believe a chart of declining union density vs time is sufficient to prove union density drives manufacturing job count? I can think of other reasons manufacturing job count might decline.
I wonder whether the argument is that union density acts as a weak greenhouse gas that does no harm.
Poor RG , seem I have rent-free vacant possession of his skull. !!
Want to try to be a complete failure, yet again, RG ?
1… Please provide empirical scientific evidence of warming by atmospheric CO2.
2… Please show the evidence of CO2 warming in the UAH atmospheric data.
3… Please state the exact amount of CO2 warming in the last 45 year, giving measured scientific evidence for your answer.
Richard is fugging great, just ask him.
I don’t down vote Mr. Greene because I don’t read his posts which, over time, have demonstrated that they are for the most part not worth reading. There are other posters here that I’m starting to ignore and skip over and others that I should ignore and skip over but I don’t because they give me a good laugh.
Richard ==> The key to the sentence you object to is “in some countries”. Japan is one of them, South Korea is problematic.
In he US, the problem is often framed as lack of younger workers to support the burgeoning number of retireees in Social Security.
There is not a lack of young US workers.
They are coming in from the south by the millions. Most illegal immigrants are young men who will get jobs here. They are the supply of low skilled labor to meet the demand for low skilled employees.
Every year, workers living in the US illegally pay tens of billions into the Social Security system with little hope of ever getting any back.
‘Illegal immigrants’ are reinforcing Social Security, not draining it – The Badger Project
Richard, you ignorant slut.
No illegal can pay social security unless they have stolen somebody’s identity, in which case of course they can collect on it. If you mean so-called asylees who are technically legal because of Brandon’s treason, you can bet that if they pay one cent of payroll tax, some America Last scumbag will be making sure that they get their money back 5-to-1.
Question – how do the illegal aliens get Social Security numbers without alerting ICE?
Kip _supported_ the argument. Go easy.
Regarding fertility rates: in measuring the dynamics of wildlife populations the preferred stat is number (or change in the number) of mature females. For instance, in birds it’s the number of fledged females that matters most. In deer it’s the does.
The reason is that the females bear the young. One buck can fertilize 50 does; one doe cannot bear the young from 50 bucks. As the female count changes, the population count changes. You can hunt a lot of bucks without changing the fawn count. Doe hunts are the control knob.
The cited paper proposes to count “the number of surviving children per female”. That’s almost right but not quite. Better would be the number of surviving (to child bearing age) females per adult female.
I’m not saying men don’t matter (please no hurt feelings, gentlemen). Except that from a population dynamics analysis point of view, you don’t.
You’re not hurting men’s rational feelings as they’ve traditionally understood women and children first down the ages. Witness filling lifeboats and who goes to war for the obvious.
However the contraceptive pill has allowed women to behave sexually as men and changed that dynamic particularly if they put off family formation and child rearing to pursue careers and wealth building just like men.(is Meetoo simply the inevitable result of the pill?). When the biological clock kicks in for most women in their 30s they discover their limited biology and attraction and where have all the men gone?
Not so much all the men but select ones their hypergamous nature desires among those peer men that might still desire them. Therein lies a growing mismatch with much singledom and childlessness for life although there is freezing eggs and the sperm donor solo mother road.
Forester ==> In the full paper, they authors do a calculation such as you suggest. Along with a great many others…by race etc.
Sea gulls can’t get birth control pills.
Seems like a perfect place for this: “not everything that can be measured is important, not everything that is important can be measured.” Unfortunately no source for this.
Every known life form is subject to cyclical population numbers. Are humans exempt from this?
ni4t ==> Probably not so much. Or, maybe, not yet. Humans have an advantage in that that have intelligence that allows them to adapt and re-adapt, repeatedly, to new challenges. Every time humans have hit what appears to be a population limit, we have found a way to overcome it, so far.
Alligators and Crocs?
At the moment, only Africa is well above the replacement birth rate or whichever statistic you prefer. It is a well known result that the exponential with the largest rate constant soon overwhelms the smaller ones. In this case, the group with the largest declining exponent disappears first. India has just passed China, as both pass slowly into extinction. It will take some time, but not much. Finally, Sub-Saharan Africans will inherit the rest of a people-empty Earth – for a second time, unless they too go negative.
whsmith ==> I can’t really follow that analysis — no country or region has a shrinking total population, as of yet. Countries, regions, are just not growing as fast.
Your point expresses what the Population De-growthers worry about.
From Worldmeter;
Japan Population 2010 128,185,275
2023 124,370,947
Population decline 3,814,328
What whsmith means is that any country or region with a birthrate less than replacement levels WILL see population decline (without immigration). Ultimately that immigration will come from Sub Saharan Africa. At present most of the immigration from that area is illegal/”refugee”.
Kip: Is TFR a “better” metric than EFR? Sure … Probably. Depends on what you’re trying to measure I expect. As Forestermike suggests (above) if you’re interested in population stability then number of biologically adult females is probably a more useful metric.
Is GAST a good metric for climate change? Well, it’s a single number. That’s what people seem to want. And it’s probably somewhat correlated with Summer high and Winter low temperatures and with rainfall at various locations. Trouble is that the correlations are different everywhere on the planet. The climate in Singapore — nearly on the equator and surrounded by tropical oceans probably doesn’t change much over a wide range of GAST. The climate in Beijing or New York City probably does change with GAST. Worse, the changes aren’t the same everywhere. Higher GAST probably means more rainfall in the Sahara. But maybe less in California.
Does GAST tell us anything? Probably. What does it tell us? I haven’t a clue. And neither, as far as I can see, does anyone else. Is there a better metric. Maybe. And what would a “better” metric tell us? Again, I have no idea.
Don ==> A pretty good summary of the state of climate science (IPCC-style). GAST, as you know, is not a measurement, it is an index of sorts about temperatures. Some indexes are useful — but indexes are never “the Thing”. They are “maps” not “the territories”.
The current in vogue GASTs only tell us how they themselves are changing. I have written, nearly endlessly, on the problems with using broad averages as representations of societal issues — they are often counter-useful. Models try to tell us what that GAST-change might mean for future Earth climates and weather.
And,m yes, the most honest answer to most questions you ask is properly: “We don’t know.”
I would suggest that the heat index, or a multidimensional graph that includes both temperature and humidity, would be a better metric than temperature alone. That is because the heat index is a better indicator of heat-stress survivability and because water vapor moderates temperature change. It also is a better explainer for energy exchanges because of the large amount of latent heat carried by water. Also, the moist adiabatic lapse rate is a better predictor of what to expect as one increases altitude in mountains, and how local ecosystems will be impacted. Lastly, daily averages from (half) hourly readings (48 or 24) should be used instead of mid-range Tmax-Tmin medians for both temperatures and humidity.
Clyde ==> As a metric for Climate Change or Global Warming? Certainly mere thermometer readings are not good measures of the danagers from local air temperatures being “too hot”.
Tmax-Tmin medians are a farcical misrepresentation of “rising temperatures — and when mish-mashed together with sea surface skin temperatures, become more so.
But no self-respecting Climate Scientist would ever utter those words.
“2. Are ANY of the so-called Global Average Surface Temperature indexes appropriate to stand as a measure of Global Climate change?”
No. Certainly not in respect to the claims about where the energy will end up from the incremental static radiative effect of rising concentrations of CO2, CH4, N2O. A rising or falling numerically computed global average surface temperature tells us nothing about how or why the trend might be up or down.
This becomes obvious by watching from space (1) and by considering the concept of energy conversion in the general circulation (2).
(1) https://youtu.be/Yarzo13_TSE
(2) https://youtu.be/hDurP-4gVrY
One more point. The ERA5 reanalysis model computes a parameter T2m – the 2-meter air temperature. Averaged over the planet, this value rises and falls about 3.8C in an annual cycle as the seasons pass. A long-term trend of, say, 0.015C per year cannot be isolated for reliable attribution. It represents a mere 1 part of 250 of enhanced warming or inhibited cooling in the annual cycle. Way too small to ever justify a claim that “we know” humans are causing it and how it is driven.
https://climatereanalyzer.org/clim/t2_daily/?dm_id=world
Dibbel ==> A sound, well-reasoned opinion.
And once again, no mention of maternal age at childbirth.
heme ==> Explain how that matters for demographic analysis?
squeezing an extra generation in every 60 years has a tremendous effect on total population for any group with a fertility rate above replacement
And God said: be fruitful and multiply
and what is often omitted is: and fill the earth.
In the 60s, effective birth control that would be under the discretion of females was deployed.
In the 60s, the population was roughly half of what it is today.
It is said by the religious devotees that God gives us what we need.
So one has to wonder if we completed the task of filling the earth and should have gone to a net zero population growth half a century ago.
That aside, fertility rates used to be based on the ability of females to get pregnant, not how many did. So, does this study account for (a) birth control and (b) the socio-psyche of the younger generation who are electing not to bring new life into a doomed world?
If (b) then the climate apocalypse is definitely a factor in declining birth rates, assuming that declining birth rates is indicative of declining fertility..
Sparta ==> Too many undefined terms in yours. What does “fill the Earth” mean? Is the Earth “full”? TFR is based on how many children a woman is likely to have in her lifetime. How many sub-Saharan Africans are “electing not to bring new life into a doomed world?” How many sub-Saharan Africans even care about the so-called Climate Crisis? Same questions for rural Chinese and rural Pakistanis and Indians?
This study does not study WHY TFR is plummeting, only acknowledges that it is. In Western Europe, TFR began to crash about 1965 – Climate Crisis was not yet a major social force, but this was when post-war Baby Boomers came into reproductive age. Nuclear War was among the dreads of the future.
“and replenish the Earth” (KJV) is not omitted when spoken or referred to in my Christian church. Is it in yours?
By the 1970s, free birth control was available to almost any woman in the US that wanted it — just go to your nearest family planning clinic — the only requirement was that the woman be at least 18 years old. This is true today as well. College and University health departments supply birth control to their students on demand (some exceptions). Over 1 million children were killed before they were born, aborted, in the US in 2023 alone.
So, TFR, births, population control and population problems are very hot topics. How we should measure that problem is the question.
Speaking of how we measure things, that should be “potential children.” Not all pregnancies go to term and result in live births. In fact, there is some thought that spontaneous abortions may exceed live births. What percentage of early-term abortions would have gone full term and resulted in live births? I think that one needs that percentage to confidently say that “over 1 million (potential) children were killed before they were born.” Does your “1 million children” figure include those that were presumably aborted with the ‘Day After’ pill, used when conception is not confirmed?
Clyde ==> A sticky issue. The people that produce these figures take these issues into consideration, and the result is a fairly accurate estimate. You can have it your way, if calling them “children” offends you, you can call them potential children.
But, I assure you, as a father, I never considered my children as anything less than children and if they had died before birth, I would have mourned just the same.
Kip,
What does “fill the earth mean?” Good question. No answer.
Too many times over the last 50 years the Church has encouraged a growing population and omitted the “fill the earth.” Example: Birth control is prohibited but fertility drugs are acceptable.
How we should measure the problem is the real question. Agreed.
But, is 8 billion people enough? Should we encourage a net zero population growth? Those are also relevant question for which I have neither an opinion or an answer.
We have learned over the past 50 years that earth’s generous resources are indeed limited and that needs to be taken into consideration.
How should we measure the problem?
All questions. No answers.
The first question is, is it a problem?
Sparta ==> Let’s acknowledge that there is no “one Church”. I suppose you mean the Catholic Church. They have their viewpoints and rules for their members. On the issues you raise, reproduction, the Catholic Church is an outlier on birth control. Many Christian churches oppose unrestricted abortion, of course, on the issue of taking the lives of unborn children. All very controversial.
And yes, the first question is “Is it a problem?” followed by “In what way? for whom?”
Then, again, you are right, if we decide it (human population) is a problem, what exactly IS the problem. How should we be measuring the problem, and not just the subject.
Will this hot topic replace Climate Change(TM)?
Retired ==> No, I doubt it very much.
What is the correlation between TFR and Effective Reproductive Rate – Labor and Effective Reproductive Rate – Reproductive? Do the proposed statistics really add very much to the conversation?
Walter ==> You want the nitty-gritt details, you have to read the paper — I give two links, website and .pdf download.
One of the major findings is that though TFR is dropping, both EFR(labor) and EFR(reproduction) have level out and are not dropping. Thus panic policy based on plummetting TFR will be incorrectly aimed.
Agreed better birthrate metrics are needed. but until then:
Currently, immigrant labor makes up 4.9% of the global population. This number has increased from 2.4% in 2000 with the total number of immgrant labor expecting to rise from 169 million to 230 million in 2030. Case in point: S. Korea has a TFR 0.70-0.88, (depending on the source), recently is working on Legislation to liberalize immigration laws in order to compete in the global immigrant labor market and bring more immigrant labor into the country due to depopulation.
Immigrants tend to see their TFR drop to the level of the host country regardless of the TFR of their country of oirgin.
So if nothing changes there will be rather large global demographic shift over the next 50 years as the world depopulation and greater competion for immigrant labor. .
All the more reason the USA should have the State of the art immigration system: legal, secure safe, just immigration system. One that prevents exploitation and matches immgrant labor to location, safe legal jobs and housing. The USA should be the place the workers from around the world want to immigrate to and work.
The other solution is to reverse the anti-human-eugenic, population control and depopluation narratives that have become louder and louder since 2008, often paired with climate propaganda and over arching and false dystopic dialectic.
There is nothing more dystopic than 18-23 years olds who expect they will never marry or have children (56% of the genz population in 2023).
The question is, who convinced them that a life alone is better? This is not just a problem of birth control and affluence…. it is a problem of propaganda a lies.
Russia’sTFR has dropped like a rock and is now paying incentives to women to have more children.
USA has always had a brighter and more hopeful future than the dystopic false reality-
lies that have been force fed to our children since 2008.
JC ==> Totally agree with the politics of “All the more reason the USA should have the State of the art immigration system: legal, secure safe, just immigration system. One that prevents exploitation and matches immigrant labor to location, safe legal jobs and housing. The USA should be the place the workers from around the world want to immigrate to and work.”
“The USA should be the place the workers from around the world want to immigrate to and work.” Legally
Retired ==> Yes, quite right.
I think that is already the case. Its just that not all who would be immigrants have the luxury of doing so by wading across a river. Those in Sub-Sahara Africa can’t walk on water and rarely have enough savings for their family to buy airline tickets to Mexico, and food while walking to the border. In that sense, the Biden policy of encouraging undocumented immigration is very racist.
yes of course America is a place people want to come and work. My point is that as the demand grows for immigrant labor will we remain competative?, (due to TFR trending lower and lower in many developed countries). I doubt we would remain competative if our border and immigration systm remains anarchistic. This is especially the case for Mexicans and South Americans who are very vulnerable entering into anarchy. Fortunatley, with the recent election, it clear only the fringe who think anarchy is a good idea. So I am confident that the USA will develop a state of the art legal, safe, secure and just immigration system very quickly. Immigration isn’t just a solutin to sustain a dwindling work force due to sub-replacment TFR. Immigration is important to America regardless of TFR and labor needs. The best solution is to revierse the declining TFR trend that is correlative to the fringe narrative that has taken center stage for the past 10-15 years.
With no ‘choice’ in that decision by you, or me.
Thank You!
A point not raised is that population growth is coupled to economic growth.
Agreed. But there are many untouchables who believe that economic growth can be sustained during depopulatin through innovation, (SI-FI fantasy realized electric storage systems, AI/quantum AI, Robotics, automation etc) In fact, this is the utropic dream of the fringe radical environmetnalist rewilding untouchables….. it’s all predicated on SI-FI becoming a reality. Their world is inspired and motivated by immature SI-FI fantasy and megalomania. Real people live in communities and families, the fringe rad envirnmental untouchables live in profound hubris alone.
Isn’t this the key reason the fringe lost the election. Out of touch.
That’s not the point my feeble attempt tried to make.
Countries with good and sustainable economic growth seem always to have good population growth to match. The correlation seems to indicate that more wealth inspires more babies.
Or, more babies lead to more consumption, which leads to economic growth?
Heads and tails of the same coin, yes.
’round and ’round we go…
Yes high levels of immigration do stimulate economies and can improve productivity numbers leading to economic growth. Baby booms are even better. Us boomers are the preimmeinent case in point. We have been riding that wave of global economic growth for 40 years we created. LOL.
A quick simple solution to a flat economy is to open the immigration flood gates. Immigration is much more predictable than tech innovation, improving worker productivity. trade, and leveraging the so called “discouraged worker” (non-institutionalized, non-dsiabled worker ages 18-55), In the US right now 22.2% of the work force is chosing not to work.
Then there is the SI-FI inspired way– AI, automation and robotics, fusion, the revolutionary Next Gen battery with ultra-centralized efficient operational control and central planning.
A baby boom is the best solution to sustaining growth.
Sparta ==> Under
Why Should we Care?
I stated, but not not emphasize, “Worldwide and National Fertility Rates are predictive of future population totals and very important for future economic condition”
The main point of this particular essay is about “Is that the right measure/right statistic?”
The author’s main focuses and areas of study is economics.
Kip,
I understand your point, but one of the values of this forum is the diversification of conversations into related topics that deviate from the thrust of the article. Some call it brain storming.
My post was not intended to disparage the report. The report triggered associated thoughts that I thought would be beneficial to share.
So, basically you are advising me to “stay inbounds.”
If that is your intent, then I shall have to go silent and offer no further comments to anything I read.
Sparta ==> I have kind of lost you here…I was responding to “A point not raised is that population growth is coupled to economic growth.” and pointed out that I did mention it in passing. Can’t quite get the “stay inbounds-ness” of that.
Kip,
You missed the point.
The coupling is economic growth leads to population growth.
The article addresses the converse relationship.
The main point of this particular essay is about “Is that the right measure/right statistic?”
That comment led to the staying inbound response.
Only with a secure border and properly enforced immigration laws.
Mr. Layman here.
When was “The Pill” invented? IUDs?
When and for how long did China have the “one child per couple” policy?
Lots of things have happened since 1950 that could effect the birthrate.
Gunga ==> Yes and yes. But, it is a good question: What caused the plummeting TFR? Not covered by the study. But, wide-spread birth control was not available in the 3rd world, China has been forced to abandon the 1-child rule.
Unfortunately, reproductive EFR and labor EFR are poor substitutes for TFR. The first assumes that all Females will have children after passing through puberty when, in fact, some will not be bale to, and many will choose not to. As to the labor EFR, the assumption is that all children, both Male and Female, will work as adults, when some won’t be able to, and some will choose not to do so. Reproductive EFR and labor EFR are upper limits – the realised values will be lower.
Retired ==> Demographics don’t make those kinds of assumptions. Demographics lets the numbers speak for themselves.
A one size fits all metric as described in the article can not be as useful as several.
Overall birth-death rate is indicative of population growth and we are seeing that globally.
Infant mortalities and, sadly, one must include abortions are another factor, weighed against successful births. The question is, at what age is a limit applied? 1 year? 2 years?
Another is the success rate at achieving fertility, aka puberty.
Another is the success rate at achieving (adult) independence.
Another is the success rate at achieving retirement.
Then there is the overall longevity distributions.
We all die, a fact of life, so the success rate of seniors would necessarily be zero.
Looking at fertility should be a trend study, no a single discrete metric.
IMHO
In this paper we offer a new measure of the number of surviving children per reproductive
age female. It is motivated by economic models, which posit that households care about the
number of children who survive—not merely the number who are born.
Well, duh!
Skimming the “magnum opus”, it would appear all they are saying is that fertility has stablized in high income countries at levels below replacement and is falling as mortality decreases in poor countries.
Sub Saharan Africa needs infrastucture to allow them to use their natural resources. At present, the only real development is by the Chinese, the latest colonialists to go after the resources. The current population is about 1.25 billion, estimated to double by 2050, while China’s will halve.
I developed as a physician and infectious disease specialists during the early age of HIV/AIDS. As I entered practice, treatments were rudimentary but of some benefit, and the measure of success was necessarily a surrogate measure that correlated well with the outcomes of HIV infection. The number of CD4 immune cells would progressively decline the longer one carried HIV till numbers fell below critical levels and unusual infections and malignancies began to afflict the infected. This became the definition of AIDS, a decline of CD4 cells below a level that would indicate immune deficiency, or the onset of an opportunistic infection or malignancy that was due to immune deficiency.
It would not have been efficient, humane or feasible to do studies of emerging therapeutics based on death rates alone. A person might live five to fifteen years between acquiring HIV and succumbing to AIDS. It would take far too long and entail far too many avoidable deaths to use morality rates to measure success. The CD4 count became the obvious surrogate as we knew HIV targeted CD4 cells preferentially, The virus carried a CD4 receptor binding site in its membrane in the same way the recent CoVID virus carried a spike protein that is suspiciously well designed to bind to a receptor widely present in the lining of human blood vessels.
So therapeutic trials of anti-HIV therapies measured success by how well they preserved CD4 cell numbers and, when new laboratory methods arose, by how well they reduced the numbers of circulating HIV within the blood. In the early days of this research the CD4 cell count alone was the primary surrogate measure.
At one point early in my career some immune signalling proteins were proposed as potential agents to fight HIV. The treatments carried considerable risk of adverse effects but were studied because they were known to raise CD4 cell counts. Here’s the thing though – they raised CD4 cell counts by way of their normal immune signalling function, and they would do so in individuals regardless of whether they carried HIV or not. It should have been obvious from the start that testing a therapy that directly affects a surrogate marker without relevance to the targeted infection and then judging the benefits of that therapy by the measure of the surrogate marker is a fools game, and so it turned out to be.
During my career I have seen this mistake made repeatedly, and often with therapeutics that turned out to be useless or even harmful. It has happened so often that I hesitate to believe now that it is due to ignorance, but rather favour the most likely explanation is opportunism. The fact that many of these misdirected “therapeutics” were, during their brief periods of prominence, some of the most expensive therapeutics on the market, only enforces my suspicions about the motivations of those who make, test and sell these agents.
And so it seems to be with the global warming scam and so many other radical environmental scare campaigns. The false prophets of doom seem to ride forward with the enthusiasm of loan sharks anticipating the false profits of snake oil and magic dust. The fact their claims of benefit are based entirely on false evidence doesn’t seem to bother them in the least.
Andy ==> Thank you for the very good and thorough example of using ‘the wrong metric’. And, I agree, I have seen many medical studies that measure use what seem to be odd placeholders for diseases or conditions that even for a layman.
GREAT Post… many Thanks.
Come winter, a few lengthy blackouts will go a long way to ‘improving’ the US birthrate.