Anne Morse Huércanos

Map of female literacy rates and fertility in Nepal:

The Sudur Paschim province of Nepal has a female literacy rate of 57%, and a total fertility rate of 1.88 🇳🇵
nepalitimes.com/here-now/nep...

"In recent years, birth rates have dropped only slightly in places where they have long been low...States that had above average fertility rates in 2014 are responsible for more than 80% of the collapse in American birth rates over the past decade."

www.economist.com/finance-and-...

Is US Fertility now Below Replacement? Evidence from Period vs. Cohort Trends - Population Research and Policy Review In this study, we contrast period and cohort approaches to answering the question: Is US fertility now below replacement? The answer would appear to be an unambiguous “yes” based on period trends in t...

The article that produced the projections:
link.springer.com/article/10.1...

4) The error ranges are pretty tight for the immediate future, because the fertility rates for women in their 40's contribute minimally. So while you have to wait until a cohort reaches 45 to get a final number, you can get a good sense by the time a cohort reaches their late 30s

3) Completed cohort fertility is only projected to reach below 2 kids per women for the cohorts of women born in 1988 and later.

2) Completed cohort fertility for the women who turned 45 in 2020 is above replacement.

Observed and projected completed cohort fertility in the U.S.

Several interesting things to note!🧵

1) Completed cohort fertility INCREASED for the cohort born between 1960 and 1975

Their full paper has a decomposition analysis which asks "are these changes due to changes in the demographic makeup of the population? Or something else?" They found that it's "something else".

Their full paper also has a regression analysis which found that the effect of being male switched directions between 2005 and 2023; males are now less likely than females to have experienced all markers of adulthood.

Housing burden costs was also significant

www.census.gov/library/work...

New work on young adults reaching adult milestones (living away from parents, in labor force, ever married, has kids.)

They found that 48% of young adults had achieved all 4 milestones in 1975, but this declined to 21% by 2024.
www.census.gov/library/stor...

Utah has the highest refined marriage rate* (49) which is over twice the rate of Louisiana (23.7).

*marriages in the past 12 months per 1,000 unmarried women age 15+
www.bgsu.edu/ncfmr/resour...

Risk-sensitive fertility: The variance compensation hypothesis Two conditions are sufficient to indicate the need for risk-sensitive, adaptive analysis: (i) the outcomes of a behavior must be unpredictable to some…

And for people who REALLY want to go down a nerdy variance-fertility rabbit hole, I recommend: www.sciencedirect.com/science/arti...

If you want a good study on replacement fertility levels needed in POPULATIONS there is this classic article: (which the authors of the new article appropriately cited): link.springer.com/article/10.1...

The fun part of this new study is how it looks at variability and random events: but variability acts very differently on large sample sizes (national populations) than on small ones (a single female)!

The study looks at the likelihood of extinction of a lineage of SINGLE female, NOT of nation-size populations.

More babies may be needed to avoid extinction, study claims Just above two children per woman was considered the minimum to sustain a population—not anymore, according to new research.

If you read this Newsweek article, you might incorrectly conclude that a new study found that countries need a total fertility rate (TFR) of 2.7 to avoid extinction.

But I read the study, and that isn't what the study shows 🧵
www.newsweek.com/babies-mothe...

If Mexico’s current low TFR is due to young women who are postponing (not foregoing) births, Mexico's TFR could very plausibly rise in a few years, and their completed cohort fertility could remain pretty stable.
Or not. Time will tell!

I wondered: What would the total fertility rate be with Mexico’s younger-age fertility rates and the U.S.’ older-age fertility rates? (1.9)

What would the total fertility rate be with Mexico’s older-age fertility rates and the U.S.’ younger-age fertility rates? (1.3)

In 2023, the U.S. and Mexico both had a Total Fertility Rate of 1.6, but the two countries have different age-profiles of childbearing.

Mexico has higher fertility at younger ages.
The U.S. has higher fertility at older ages:

Trends in the percentage of U.S. adults age 25-34 living with nonrelatives, or with “other relatives”:

Trends in the percentage of U.S. adults age 25-34 living alone and living with a parent:

A slight tick downward in the % of U.S. adults age 25-34 living with unmarried partners (after a long, steady increase):

No decline in the % of people ages 25-34 living with a spouse in recent years: 👩🏽‍🤝‍👨🏾🏠

Other interesting results if you scroll through:

Women are more likely to live with a spouse or “other relative.”

Men are more likely to live with a parent, alone, or with non-relatives.

Users of the Demographic and Health Surveys, please let your voice be heard!

Charles Westoff writing 42 years ago (!) on fertility decline in the West:

jstor.org/stable/1972897…

I finally made it over to Bluesky! I'm here to keep sharing fun fertility facts.

To start, a hot-of-the presses report shows increases in first-time parents using paid parental leave in the U.S.--especially for men: 📈👶

www2.census.gov/library/publ...

Global Population Estimates Vary but Trends Are Clear: Population Growth Is Slowing It took 13 years for the world population to go from 7 billion to 8 billion but it will take an estimated 14 years to add another billion amid slowing growth.

The world at 8 billion, by yours truly.🌎

www.census.gov/library/stor...