September 18, 2025 - The top 20% of counties that voted for Harris had a TFR of 1.37. State-level data reveals a similar relationship between partisanship and fertility. Democratic states have much lower fertility rates than Republican states.

3 days ago - The final explanation for the partisan fertility gap stems from the fact that, over the past few decades, the two major political parties have become more and more geographically sorted. Democrats tend to live among Democrats; Republicans, among Republicans. Jacob Brown, a Boston University political scientist who studies this phenomenon, told me this doesn’t necessarily mean Republicans and Democrats physically moved away from each other. Instead, the two parties shifted over time such that they have come to represent different types of people—the Democratic Party appeals to people in cities; the Republican Party targets rural voters. Now people who belong to each party disproportionately socialize with other people of the same party. Less than a third of Democrats, according to one recent survey, have “at least some” Republican friends. This sorting means that initially small differences in fertility between liberals and conservatives can compound over time.

When we compare Republican to Democratic-leaning counties in Figure 3 we find some · evidence that relative Democratic fertility falls, with an average quarterly effect of 0.087 · births per 1,000 women (0.6% of the 1999 average birth rate).

2 weeks ago - Left-leaning Americans are averaging far fewer children than conservatives, whose birth rates hold steady near the 2.1 replacement level. Evolutionary demographers Martin Fieder and Susanne Huber recently pinpointed the precise moment this ...

November 18, 2020 - The use of state controls (and some robustness tests I ran in large states with many counties) suggests this effect isn’t driven by unique features of states: within Red states or Blue states, and controlling for county racial and ethnic characteristics and population densities, Republican counties have higher birth rates. This is particularly astonishing given that Democrats perform very well in counties with many Hispanic and black voters, who have higher birth rates than non-Hispanic white Americans (and indeed, the more non-Hispanic whites in a county, the lower its birth rate in my models).

May 25, 2022 - The use of state controls (and some robustness tests I ran in large states with many counties) suggests this effect isn’t driven by unique features of states: within Red states or Blue states, and controlling for county racial and ethnic characteristics and population densities, Republican counties have higher birth rates. This is particularly astonishing given that Democrats perform very well in counties with many Hispanic and black voters, who have higher birth rates than non-Hispanic white Americans (and indeed, the more non-Hispanic whites in a county, the lower its birth rate in my models).

April 9, 2024 - The partisan identification of ... parties: 49% of registered voters are Democrats or lean to the Democratic Party, and a nearly identical share – 48% – are Republicans or lean to the Republican Party....

June 20, 2025 - The birth gap between the states that voted Republican and Democratic in the past presidential election has fallen from about 475,000 births in 2015 to approximately 294,000 births in 2023.

December 19, 2024 - The evidence suggests causality flows in both directions, as we noted in 2020. Additionally, there are further structural variables to consider. Differences in education levels, for instance, explain much of the variance in birth rates between Republican and Democratic counties.

The longitudinal · correlation studies provide two significant findings: (1) the correlation between fertility · and GOP performance rose steadily between 1940 and 1980, with Republican candidates · benefiting from the Fertility Gap in every election from 1960 onward; and (2) from 1992 ·

July 1, 2026 - It is well established that children are more likely to adopt the ideologies of their parents than chart their own path ... True, but: "On average, Democrats are having 1.53 children, compared with 1.86 for Republicans."

October 30, 2024 - The birth gap between the states that voted Republican and Democratic in the past presidential election has fallen from about 475,000 births in 2015 to approximately 294,000 births in 2023.

Democratic counties, a shift amounting to 1.2 to 2.2% of the national fertility rate. In addition, Hispanics see fertility fall relative to non-Hispanics, especially compared to rural or evangelical ... Republicans’ surged from 12 to 46% (Gallup, 2017).

October 27, 2025 - The 20 U.S. counties with the largest margins for Trump had an average total fertility rate of 1.76; the 20 counties with the highest margin for Harris had a TFR of 1.37 in 2024. Yenor and Stone infer, “Democrats increasingly seem to be the ...

October 7, 2024 - From the article: A study published in the Journal of Marriage and Family has found that political identity is increasingly influencing the number of children young adults desire to have. Spanning three decades, the research found that young Republicans consistently expressed a stronger desire for larger families compared to their Democratic counterparts, with this gap widening over time.

The paper’s authors find that this difference between Republican versus Democratic babies conceived in the first two years of the Trump presidency amounts to between 1 and 2% of the national birth rate.

July 8, 2022 - “The gap is actually 41 percent.” Data on the U.S. birth rate from the General Social Survey confirms this trend — a random sample of 100 conservative adults will raise 208 children, while 100 liberal adults will raise a mere 147 kids.

December 15, 2025 - On the other hand, senators with four or more kids constitute only 8% in the Democratic Party and a whopping 26% in the Republican Party.” · It is not just politicians but voters that show this pattern of conservatives having more children.

November 22, 2024 - “Republican states (those that Trump won in 2020) generally have markedly higher fertility rates than Democratic ones (those that Biden won), suggesting that more men and women feel confident about starting and raising families in red states ...

April 9, 2024 - The youngest age cohort at the time – voters in their 20s, born in the 1970s – had the exact same partisan makeup. Only one age cohort stood out as different – those born in the 1960s (then in their 30s) were more Republican, on balance, than other age groups. Ten years later, in 2009, the then-youngest age cohort (people born in the 1980s, then in their 20s) was clearly more Democratic-oriented than older groups, but there was little difference between the older cohorts (though those born in the 1960s remained slightly more Republican than both groups older and younger than them). Now, and for the last several years, a starker – and more linear – age pattern is evident. Those born in the 1990s (now in their mid-20s to early 30s) are more Democratic than those born in the 1980s, who are in turn more Democratic than those born in the 1970s.