Posted on July 10, 2024

Diversity Up, Fertility Down?

Steve Sailer, Taki's Magazine, July 10, 2024

The U.S. total fertility rate briefly exceeded the replacement rate of 2.1 babies per woman’s lifetime during the Housing Bubble of 2006–2007 but has since dropped steadily, hitting a new record low of 1.62 in 2023. Total births fell 2 percent last year to under 3.6 million, the lowest total since the Birth Dearth of the 1970s:


Now, two finance professors, Umit G. Gurun and David H. Solomon, have posted a preprint of their paper “E Pluribus, Pauciores (Out of Many, Fewer): Diversity and Birth Rates.” They suggest there may well be a causal connection between the two major demographic trends of the age: the growth in diversity and the decline in fertility:

In this paper, we document a new and important stylized fact linking the central demographic changes of our time. Women living in areas of higher racial diversity robustly have fewer children.


After all, you are not supposed to say bad things about diversity, which is, as Dan Quayle said, our strength. Recall the comic 2006 incident in which famed Harvard political scientist Robert D. Putnam, author of Bowling Alone, admitted that he had hidden away for five years the results of a big survey he’d done because it revealed that increased demographic diversity led to lowered social trust.

Of course, diversity could hardly explain all the declines in fertility seen around the world: For example, South Korea remains pretty Asian while its total fertility rate has dropped well below one baby per woman.

But Gurun and Solomon might be onto something when it comes to explaining what’s going on in the United States. They suggest that if people prefer (whether consciously or unconsciously) to marry a member of their own race, the higher the percentage of people of their own race they meet, the more likely they are to find Mr./Miss Right, and the sooner that happy day is to arrive.


The authors call this tendency to be more likely to marry within your own race “homophily.” {snip}

As the number of people of different races in each area has increased, people have fewer encounters with others of their own race. Various studies document that people on average have a preference for homophily—they prefer to marry those with similar characteristics, particularly people of the same race…. If the number of potential same-race partners drops in an area, then either one incurs higher search costs to find a good match, or the quality of matches decreases, or both. While the evidence for homophily is large, the possibility that this may have implications that link the rise in diversity and the decline in birth rates does not seem to have been considered.

A noteworthy exception to the general pattern of homophily is that Chinese and Japanese women tend to have more children when there are lots of white guys around.


The two researchers looked at differences in diversity and birth rates across the United States. They ran their data through all sorts of statistical controls to adjust away any likely confounders. They still conclude:

We find that the average racial isolation explains 44 percent of variation in the US total fertility rate since 1971, and 89 percent since 2006. The predicted decline between 2006 and 2021 based on the coefficients is 0.426 children per woman, very close to the actual decline of 0.444. Diversity is large enough as a factor to potentially explain a large amount of birth rate time series variation, especially the most puzzling changes in recent years.