One curious aspect of American political geography is that variables that predict partisanship at the individual level often do a poor job of predicting the partisan balance at the state level. African Americans are among the most reliable Democratic voters, but the region with the largest African American population (the Deep South) is reliably Republican; wealthy Americans are, on average, more likely to vote Republican, yet the Northeast, where so much of the nation’s wealth is concentrated, consistently gives its Electoral College votes to Democrats. This pattern makes it difficult to find variables that accurately predict whether a state falls in the Red or Blue camp. One of the few such variables is the median age at first marriage.
As I showed in an article for Party Politics, median age at first marriage for women had a strong, linear relationship with support for Bush at the state level in the 2000 presidential election. I found a similar relationship when looking at county-level and individual-level data. And this relationship remained statistically significant and substantively important despite controlling for a myriad of additional variables.
Although comparatively new (it did not garner much scholarly interest until the 1980s), the marriage gap is now one of the more consistent elements of American politics. I have conducted a similar analysis for all subsequent presidential elections. Although the 2016 presidential campaign upended many expectations, in this regard, it was business as usual, as we see in the figure below.
Although there was a slight decline in the correlation between these two variables in the 2016 election compared to 2012, this was almost entirely due to Trump’s poor performance in Utah compared to Mitt Romney—a significant percentage of Utah voters supported conservative third-party candidate Evan McMullen.
The follow-up question, of course, is what predicts earlier marriages? This is an important question, given that, if the relationship between marriage and Republican voting is not spurious, then the decline of marriage in the United States represents yet another long-term demographic problem for the GOP.
When considering this question, it is easiest to say that “culture”—however defined— explains different family formation trends, and that culture is the reason we see a partisan marriage gap. That is, in some states, people are more religious and traditionalist, which explains both the early marriages and the greater support for Republican voting. There is definitely some truth to this argument. For example, the large Mormon population in Utah explains both the state’s political conservatism and its high marriage and fertility rates.
These cultural explanations, however, neglect the scholarly literature demonstrating that many economic variables predict trends in marriage and the family. One such variable, which government policy can influence, is home affordability. To my knowledge, the blogger Steve Sailer was the first person to make the connection between home values, marriage rates, and vote choice. However, the existing scholarly literature supported this hypothesis.
Social scientists have noted the relationship between the availability of spacious housing and family size since at least the 1930s, and it makes intuitive sense. We typically associate marriage, and especially children, with single-family homes rather than apartments and condominiums. One does not need to be a scholar to make this connection; anyone who has spent time with multiple toddlers in a confined space knows why large families prefer large houses, ideally with yards.
This theory also partially explains other elements of American political geography, such as why coastal cities tend to be more Democratic than large cities farther inland. Metropolitan areas with natural barriers to growth will experience a faster increase in property values; cities like Seattle that are constrained by both water and mountains quickly become family unfriendly because of the paucity of affordable single-family homes. In contrast, inland metropolitan areas like Dallas, which can easily expand in all directions, can keep their housing costs down. By being family friendly, these inland cities tend to be more Republican than their coastal counterparts.
The plausible hypothesis that affordable housing leads to more marriages which lead to more Republicans voting must be viewed with some skepticism, however. Although these correlations are definitely real, it is much harder to prove the causal relationships. For example, it may not be that marriage causes people to become Republicans. Instead, there may be personal attributes associated with both early marriage and vote choice. Again, greater religiosity could be driving both.
Similarly, it may not be the case that cheap housing causes people to form families at an earlier age. Instead, divergent migration patterns may explain this geographic divide: recently or soon-to-be married people may exit those cities and regions with a high cost of living and settle where spacious housing is more affordable. Varying prices may determine how married and unmarried Americans are geographically distributed, but may not have much influence on the total number of marriages.
Thanks to the growing stack of research on these topics, it is becoming increasingly clear that these relationships are not spurious. It appears that marriage does change political attitudes, for example. Moreover, while the different family formation patterns we see in different housing types can be partially attributed to selective moves, this is not the entire story. Affordable housing itself promotes earlier family formation and larger families.
Given these findings, it seems that a pro-marriage agenda is the politically smart move for the GOP, and a key element of such an agenda would be home affordability. I would urge caution for those with such ideas, however. Pushing people into homes does not promote family formation and fertility if doing so leads to massive financial burdens. Furthermore, the government does not have a stellar record of accomplishment when it comes to tinkering with lending standards and other policies surrounding home ownership.
Regardless of what policymakers ultimately decide to do with these findings, prognosticators looking to forecast the future of American politics should keep a close eye on trends in the American family.
George Hawley is an assistant professor of political science at the University of Alabama. His books include Demography, Culture, and the Decline of America’s Christian Denominations and Making Sense of the Alt-Right.