George Hawley, a professor of political science at the U. of Alabama, writes:
Although you wouldn’t know it based on which elements of my research agenda get media attention, the subject I have worked on more than any other since grad school is the relationship between family formation and partisan politics. Specifically, I argued in my dissertation, my first peer-reviewed article, and my first two books that the GOP benefits when people form family units at an early age.
However, when it comes to the median age at first marriage and vote choice at the state level in presidential elections, you haven’t recently needed to include that caveat. To my knowledge, no variable has ever had such a strong, linear connection to state-level vote choice in presidential elections than the median age of first marriage for women. In 2012, this simple two-variable regression had a ridiculous R-squared of 0.72. That’s a number you simply don’t see in political science with such a simplistic model.
The 2016 election was a little different, however. The relationship was still there (if it totally disappeared, then the world really had been turned upside-down), but it was weaker. The R-squared dropped to 0.57. That’s still really good, but not amazing.
And here’s Hawley’s 2011 paper testing my Affordable Family Formation theory of Presidential voting.
Here’s my 2013 VDARE article on the 2012 election.