Environmentalism Needs Pronatalism

Since New York Representative Alexandria Ocasio-Cortez pondered the question out loud last month, the idea that climate change makes it immoral to have children has gotten a great deal of play in major media outlets. The most serious pushback, first offered by Tyler Cowen in Bloomberg and echoed by Senator Mike Lee on Tuesday, centers on Nobel-prize-winning economist Paul Romer’s idea that more people means more innovation, and more innovation is necessary to fight climate change.

Despite the ridicule coming at Senator Lee from the usual places, Romer’s idea is well-supported as far as theories of innovation go. Even so, it’s understandable why proponents of decisive climate action might not be willing to bank on a promise of some unspecified future innovation. Is it smart to put so much trust in something that we don’t even know exists yet?

In fact, there’s an even more concrete and compelling reason why a campaign to reduce birthrates is likely to hurt the environment: If environmentalists stop having children, the world will have fewer environmentalists.

How Social Pressure Works

Most people exercise social pressure in a more or less indiscriminate way. If it would be good for the world that people do [x], then I’ll try to convince people to do [x].

Not all people, of course, are equally receptive to social pressure. Most of the time this doesn’t matter. When we try to exercise pressure on people to consume less, to buy more efficient cars, or to use one square of toilet paper when visiting the loo, every bit helps, and if some people don’t listen— if some people scoff, or continue to use multiple squares— at least we’re no worse off than before.

The situation is different, however, when the pressure pertains to having children. Suppose we could quantify the quality of being receptive to social pressure. In fact, this quality is part of what personality researchers have identified as conscientiousness, one of the five core dimensions along which personalities can vary.

So who’s most likely to respond to social pressure to consume less?— the most conscientious. Who’s most likely to use one square of toilet paper?—the most conscientious. And who’s most likely to have fewer children if politicians and journalists set it up as the moral thing to do?— naturally, the most conscientious. People who read thinkpieces about environmentalism—including you, dear reader— are probably some of the most conscientious in our society today.

Now here’s the problem: conscientiousness has been estimated to be about 44% heritable. In other words, 44% of the variation in how receptive a group of children is to social pressure can be explained by the receptivity of their parents, with most of the rest apparently due to random variation. In short, if you’re more conscientious, your children are likely to be more conscientious as well.

So here’s how the story plays out:

1. Politicians and journalists tell people to consume less and have fewer children.
2. The most conscientious people take this message to heart, consume less, and have fewer children.
3. The next generation is slightly less conscientious on average, and less inclined to watch their carbon footprint. The generation after that is even less so.
4. After a few generations, if anyone is still preaching the gospel of low consumption, there’s no one left who cares to listen!

This is a problem that economists call adverse selection. It’s a problem that runs through finance, insurance, drug policy, and a whole host of other arenas. No matter the problem you’re trying to solve, adverse selection can mean that the obvious solution might be the worst thing you could do in the long run.

(I’m going to assume here that conservative fears about this social pressure leading to forced sterilization are indeed unfounded, and that the campaign will remain one of social pressure. Coercive policy could indeed solve the adverse selection problem, but at a moral cost so great that I would not venture to tar most environmentalists with it.)

Practical Implications

Let’s assume the worst estimates of the carbon footprint of having a child, and assume that we can’t count on any technological breakthroughs as in the Romer story. Even in this worst-case scenario, the adverse selection problem means that anti-natalism is still a cataclysmically bad environmental strategy. It’s not likely to make a significant impact on the number of people in the world in the long run, but it is likely to ensure that those people are less conscientious, and—therefore—less likely to care about the environment.

Instead, it’s necessary to be smart about who’s listening when we exercise social pressure on the question of childbearing. Here are a few practical implications.

1. If the adverse selection story is true, it means that running pieces on the environmental cost of having children is one of the most harmful possible environmental strategies. Push back. Don’t let the anti-natalist case go unanswered. Write letters to the editor; call your representatives; challenge your conscientious and environmentally engaged friends on Facebook and in real life.
2. Have more children. I feel confident saying this indiscriminately, knowing that those who read this and take it seriously are likely to be more conscientious than average. In the long run, the only way to ensure that the future earth is filled with the kind of people we’d like it to be filled with is to make them ourselves.
3. Exercise positive social pressure. Encourage your pregnant friends. Tell them they’re doing the right thing. You can feel confident doing this indiscriminately too, for the same reason that I do it confidently here.

Conclusion

At the end of the day, none of us—either by our own fertility decisions or by exercising social pressure—can meaningfully affect the number of people in the world in the long run. What we can affect by our own fertility decisions and by exercising social pressure, is what kind of people exist in the world in the long run. For the sake of the earth’s climate, ecosystems, and future generations, I can only hope that shortsighted journalists and politicians do not succeed in convincing those who care deeply about the environment to deprive the world of future environmentalists.