Demography is (political) destiny? Or, fertility differences between Democrats and Republicans

Boris forwarded an interesting column by Arthur Brooks. I’ll excerpt it, then give my thoughts. Brooks writes:

Liberal politics will prove fruitless as long as liberals refuse to multiply. . . . On the political left, raising the youth vote is one of the most common goals. This implicitly plays to the tired old axiom that a person under 30 who is not a liberal has no heart (whereas one who is still a liberal after 30 has no head). . . .

But the data on young Americans tell a different story. Simply put, liberals have a big baby problem: They’re not having enough of them, they haven’t for a long time, and their pool of potential new voters is suffering as a result. According to the 2004 General Social Survey, if you picked 100 unrelated politically liberal adults at random, you would find that they had, between them, 147 children. If you picked 100 conservatives, you would find 208 kids. That’s a “fertility gap” of 41%. Given that about 80% of people with an identifiable party preference grow up to vote the same way as their parents, this gap translates into lots more little Republicans than little Democrats to vote in future elections. Over the past 30 years this gap has not been below 20%–explaining, to a large extent, the current ineffectiveness of liberal youth voter campaigns today.

Alarmingly for the Democrats, the gap is widening at a bit more than half a percentage point per year, meaning that today’s problem is nothing compared to what the future will most likely hold. Consider future presidential elections in a swing state (like Ohio), and assume that the current patterns in fertility continue. A state that was split 50-50 between left and right in 2004 will tilt right by 2012, 54% to 46%. By 2020, it will be certifiably right-wing, 59% to 41%. A state that is currently 55-45 in favor of liberals (like California) will be 54-46 in favor of conservatives by 2020–and all for no other reason than babies.

The fertility gap doesn’t budge when we correct for factors like age, income, education, sex, race–or even religion. . . .

My thoughts:

1. First off, it’s interesting that these differences are so large. It would be interesting to look at these differences over time (I assume Brooks is writing a longer paper with these trends).

2 Considering this as a long-term phenomenon, I’d expect the parties to gradually move to the right to stay where the voters are. So I wouldn’t think the Democrats are doomed, but rather that they’d have to move to the right as necessary. And, indeed, our calculations show that the Democrats would do better by moving slightly to the right.

3. Right now, however, the Republicans are more to the right of center than the Democrats are to the left of center (at least, as perceived by the voters on some key issues); see Figure 4 of this paper. So, in the short term, it appears that the parties are a little ahead of themselves in moving to the right.

4. I recently linked to a Pew Research Center survey that had the following result:


This would seem to contradict the idea that the youngsters are mostly Republicans. Things might change in future years, of course, but the graph suggests that things are a little more complicated than a simple inheritance of party ID.

5. Finally, political policies are also affected by factors other than public opinion. Just to consider two examples: communism and the current Iraq War are two policies that haven’t seemed to work so well and have declined in popularity, presumably for policy reasons. This is mediated by public opinion but my point here is that the underlying success of various policy proposals can have an impact–it’s not just party ID that will determine things. To think about this in another direction, sometimes popular positions do not get adopted (for example, raising the minimum wage in the U.S., or instituting the death penalty in Europe), partly because of interest groups, political maneuvering, external norms, etc.

Way back when, people considered the demographic trends in the other direction, and expected that universal suffrage would lead to confiscatory taxation (the lower 60% of income could tax the upper 40% out of existence, and this would just continue because the poor have more kids than the rich), but it didn’t happen.

To summarize: the trends that Arthur Brooks identifies are interesting, and I’d assume they’ll have some effect; at the same time, I’d be wary of using them to forecast too directly since the parties have the opportunity to change their positions while this is all happening.

2 thoughts on “Demography is (political) destiny? Or, fertility differences between Democrats and Republicans

  1. Some thoughts.

    1. Yes, it's very curious that the difference is so big. Especially since if it is true that income is inversely related to Republicanism (which is still true as per our Red-Blue paper), AND poor people have more children than rich people (I think this is true).

    2. Yes, parties can and do move policy positions. However, since there are "external factors" like the ones you identify in point 5 — they may not. Perhaps the polarization of elites (bloggers?) may prevent a politically-wise rightward Democratic shift.

    4. Doesn't the plot here mix generations? Perhaps in the past the youth were more Democratic, but in recent decades, as Republicans have become relatively more fertile, this may no longer be the case.

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