We know that culture drives fertility more than money these days, but what specifically is it about culture? In wonderful report published today, @FamStudies surveyed 10,000 people around the world to learn what it is about culture that leads people to have kids or not. 🧵.

A brilliant discussion of how demography will shape economics with leading demographer @MorlandDemog, author of the new book Bust: The Economics of Population Decline. In our new world of low fertility, demography will drive economic conditions while culture drives demography.

Why Strict Traditionalism Doesn't Mean High Fertility Two charts by @WorksInProgMag show that norms against mothers working don't lead to high fertility in the context of an advanced economy. South Korea has such a strong cultural expectation against mothers working that 62% of Korean women quit their jobs when they become mothers. To an old school traditionalist that might sound great, except that we know South Korea's fertility is one of the lowest in the world. South Korea is no outlier. The five countries with the lowest rates of maternal employment in the OECD are Chile, Italy, South Korea, Mexico and Turkey. Their fertility rates in 2025 were 1.0, 1.14, 0.8, 1.25 and 1.42 respectively - all far below the US level of 1.6. How does Israel, with a TFR in 2025 of 2.88 score on employment of mothers? Some 75% of mothers of pre-school-age children work in Israel, well-above the OECD average! This seems really strange! Why would the countries where mothers drop everything else to focus on raising children have the lowest fertility? The answer is this: if women are forced to choose between a career and motherhood, a large share of women will choose only a career, especially if they have committed many years to education and advancement. So - are the trads wrong? Is the traditional arrangement where the father is the breadwinner and the mother raises kids bad for fertility? No! Those types of households tend to have very high fertility! Then how do you square this circle? The answer is to build a society that embraces both family arrangements at the same time, the traditional stay-at-home full-time mother and the working mother. The more viable different paths to motherhood there are, the higher national fertility will be!

It is an astonishing fact that half of all births in several Canadian provinces are to mothers not born in Canada. Immigration is 4-7 times native births. Canada is witnessing one of the fastest demographic transformation in history and will soon be less European than Mexico.

Many people are saying

If @elonmusk is really serious about pronatalism and boosting birth rates, he should nudge @Tesla into building a cool electric minivan that can carry a big family in safety & comfort. I've been posting about this for years. Here @MoreBirths makes the case for a Tesla minivan in much richer detail. (With all due respect to the Model Y, it's just not optimized for big families -- and big families are what we need.)

With the world in awe of Tesla, is it time for @elonmusk to introduce a car for larger families? In my newest article, I show how the rise of the minivan contributed to a mini baby boom in America in which fertility rose by 0.3 births per woman for two decades. Read more below!

How the birthrate crisis will devastate the world economy in 4 maps One of the clearest measures of economic power and sophistication is manufacturing. Making advanced products requires very high levels of competence and large companies of full of highly skilled people doing difficult jobs well. @arctotherium42 created a series of cartograms - where the size of each country is proportional to the value of its manufacturing output in different categories. Look at steel, machine tools and semiconductors, the very things that build our modern, technological world. East Asia dominates these manufacturing categories with Europe and the US also having a share. The rest of the world produces very little of any of these. Compare this against births around the world. The countries responsible for making the things our world depends on constitute a small and shrinking share of global births. The countries with most of global births, meanwhile, generally lack the capacity to produce these things that are foundational in our global economy. Manufacturing drives much of the rest of the economy. Modern agriculture, energy production, travel, communications and more all rest of the foundation of sophisticated products. The fertility collapse of the countries that make most advanced goods, if not reversed, will be catastrophic for the world economy.

There are a handful of countries that—on their own—have more children per year than the entire EU. These are India, China, Nigeria, Pakistan, the Democratic Republic of the Congo, Indonesia, and Ethiopia.

The ability to include inline images in longer posts was a wonderful feature of X that is sorely missed. It was an important tool that made posts much better and I hope it returns!