by Brian Tomasik
First written: 4 Aug. 2012; last edited: 31 Oct. 2013
The present-value cost of having a child may be in the ballpark of $0.5 million when both direct expenditures and opportunity costs are considered. This shows the value of using the most effective birth-control methods, like the implant and vasectomy. Sterilization methods have the additional advantage of being a self-commitment mechanism against compromising on your ideals later in life.
What is the financial cost of having a child? To many people, it's the amount of money spent on food, clothing, housing, transportation, tuition, and so on. One calculator suggests that these costs might total ~$500K for a kid in the US who goes to private college, although I believe that figure does not account for the time value of money, and the cost-of-living estimates may be too high. A better estimate might be more like ~$150K (assuming ~$12K of costs per year over 18 years at a 5% real rate of return) plus ~$60K (based on ~$160K for college ~20 years in the future using a 5% real rate of return).
Of course, economists and utilitarians will notice an additional cost: The opportunity cost of the time spent parenting. If you want to raise your child well, then this time expenditure might begin even before conception, as you research optimal health and nutrition during pregnancy. Then there are 9 months of pregnancy (which requires additional health-care visits and sickness), weeks or months of paternity/maternity leave from work, months of sleepless nights attending to your crying baby every two hours, pediatrician visits, playing with your toddler or traveling to daycare, shopping for baby clothes and toys, researching pre / elementary / middle / high schools, helping with homework and interacting with teachers, spending quality time with your kid on the weekends, taking your kid to events and friends' houses, going to school functions, researching and visiting colleges, helping with college applications, transporting to and from college, giving advice on jobs, and everything else in between.
Say these take an average of 3 hours a day between you and your partner, 7 days a week, for 19 years. That's 21 hours a week, and with the same amount of time, you might have been able to earn, say, ~$40K per year, or ~$30K after taxes. Again using a 5% real rate of return for discounting, that amounts to ~$380K of forgone cash right now.
There could also be costs of reduced ambition. For example, maybe you would have become a CEO who travels the world constantly, but you don't want to be the kind of mom who never sees her kid, so you aim for something less remunerative. Depending on the circumstances, this could add up to many hundreds of thousands of dollars or more.
And then what about your inheritance? Are you sure you're going to leave no assets to your kid, in contradiction of social custom? What if your mind changes by the time you're 70 years old?
Now, of course there might be utilitarian benefits from having a kid. The main one is that your kid might grow up to share your ideals and spend his life working on them. But I wouldn't count on it. Given how relatively few people focus on reducing suffering from an efficiency mindset, the chance that your kid spends his life doing the same sort of work as you seems fairly low. There is a nontrivial contribution of genes to personality and hence moral convictions, but this suggests you should become a sperm/egg donor rather than having kids yourself. And if you think environmental influence matters more, then you could go off and inspire some of the billions of other young people in the world, a minority of whom will be more receptive to your ideas than your own kid would be.
In light of the above discussion, it seems plausible that the costs of having a child could be in the ballpark of $0.5 million. In fact, the costs could be higher depending on what you give up, but let's stick with $0.5 million in the subsequent calculations.
With $0.5 million at stake, birth control begins to appear extremely important. Consider the table in Wikipedia's article on "Comparison of birth control methods." Male condoms have a perfect-use failure rate of 2% per year. 2% of $0.5 million is $10,000 per year. The combined oral-contraceptive pill has a perfect-use failure rate of 0.3% per year, or $1,500. And if we talk about typical-use failure rates for these methods, we're into $75K and $40K per year, respectively. (That's more than many people's salaries.)
Now, these costs may be somewhat inflated, because even if pregnancy occurs, you might have an abortion, or you might leave the child for adoption. Multiply the above numbers by the probability p that you refuse to give up the child. You might think p is small, but consider that many women find abortion to be a taxing decision, and maternal hormones promote attachment to newborns, so it's good to avoid being overconfident that you would give up the child.
Fortunately, there are some highly effective birth-control methods according to Wikipedia's table, especially "the implant," which has a typical-use failure rate of 0.05% per year, or $250*p annually. Often it's covered by health insurance.
Now, maybe there's some uncertainty in the exact failure rate, since this can vary from study to study. So instead of using 0.05% as a point estimate, suppose we take the expected value of the failure rate relative to a Bayesian probability distribution that's symmetric on the log scale. In particular, to make things really simple, suppose we think there's a 1/3 chance that 0.05% is correct, a 1/3 chance that it's 10 times too low, and a 1/3 chance that it's 10 times too high. Then the actual expected failure rate is (1/3)(0.5%) + (1/3)(0.05%) + (1/3)(0.005%) = 0.19%. This amounts to $950*p per year.
You might combine two methods together. For example, say you also do a vasectomy, with a typical-use failure rate of 0.15%. Let's again account for uncertainty and make this (1/3)(1.5%) + (1/3)(0.15%) + (1/3)(0.015%) = 0.56%. Alone, this would be $2800*p per year, but together with the implant, it's only $5.32*p. Pretty good.
An additional advantage of a vasectomy (or tubal litigation, though it's a more involved procedure) is that it's nominally permanent. (Yes, vasectomy reversals can be done, but they don't always succeed, and at least the burden and out-of-pocket expense might make you think twice about attempting it.) This could be extremely valuable if your future self loses its discretion and decides that it wants to spend $0.5 million or more on a child. (Heaven forbid two!)
It may feel now like you would never want kids, but it's easy to be overconfident about one's future emotions.
Robin Hanson, "Future Fertility":
Many a young woman has looked inside herself, decided that she just doesn't want kids, and went on to live her life under that assumption. But a decade or so later, her biological clock suddenly went off and she found herself very much wanting kids. I've seen this happen several times. None of us should be very confident about what introspection tells us we will later want. Evolution has designed us to express different genes at different ages; we just can't know what future genes we have been designed to express.
"Baby Fever: Does The Biological Clock Exist?":
A recent study has found baby fever is, in fact, a real thing and it affects a large number of people -- men included. "Baby fever is this idea out in popular media that at some point in their lives, people get this sudden change in their desire to have children," lead researcher Gary Brase says in a release featured on The Globe & Mail. "While it is often portrayed in women, we noticed it in men, too."
Of course, sterilization doesn't preclude the possibility that you'll decide to adopt kids, but at least it eliminates the component of baby fever that derives from the selfish evolutionary desire to pass on your own genes.
Finally, it's worth noting that we shouldn't shun people who decide to have kids. Many utilitarians among us will one day make that choice. Requiring childlessness as a membership criterion for the utilitarian club is one sure way to keep down participation rates. The important thing is just to point out the tradeoff that's being made. Having kids is not unlike, say, someone deciding to take a job that earns $100K per year instead of $140K per year. We do the best we can within the bounds of what our willpower and lifestyle sustainability allow.
 If we adopt a broad view about what types of human undertakings are socially valuable, then it becomes more plausible that a child who is smarter than average and raised in a better-than-average environment would contribute a lot more than average to future society. That said, many contributions that people make have unclear signs, especially technological progress, so it's not completely obvious if the differential talent of your child would be net good or bad on balance.